Google Git
Sign in
cobalt / cobalt / abeb60ef8f6112b2bef492d1e232d9894c8f4948 / . / src / cobalt / media / filters / source_buffer_stream.cc
blob: 6327853071ad64e6b69027ced12bfa0d0697d22c [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "cobalt/media/filters/source_buffer_stream.h"
#include <algorithm>
#include <map>
#include <sstream>
#include "base/bind.h"
#include "base/debug/trace_event.h"
#include "base/logging.h"
#include "cobalt/media/base/timestamp_constants.h"
#include "cobalt/media/base/video_resolution.h"
#include "cobalt/media/filters/source_buffer_range.h"
namespace cobalt {
namespace media {
namespace {
// The number of ms to crossfade before trimming when buffers overlap.
// Note that this was defined inside AudioSplicer. Re-define it here to avoid
// dependency on AudioSplicer.
const int kCrossfadeDurationInMilliseconds = 5;
// An arbitrarily-chosen number to estimate the duration of a buffer if none is
// set and there's not enough information to get a better estimate.
const int kDefaultBufferDurationInMs = 125;
// Limit the number of MEDIA_LOG() logs for splice buffer generation warnings
// and successes. Though these values are high enough to possibly exhaust the
// media internals event cache (along with other events), these logs are
// important for debugging splice generation.
const int kMaxSpliceGenerationWarningLogs = 50;
const int kMaxSpliceGenerationSuccessLogs = 20;
// Limit the number of MEDIA_LOG() logs for track buffer time gaps.
const int kMaxTrackBufferGapWarningLogs = 20;
// Limit the number of MEDIA_LOG() logs for MSE GC algorithm warnings.
const int kMaxGarbageCollectAlgorithmWarningLogs = 20;
// Limit the number of MEDIA_LOG() logs for same DTS for non-keyframe followed
// by keyframe. Prior to relaxing the "media segments must begin with a
// keyframe" requirement, we issued decode error for this situation. That was
// likely too strict, and now that the keyframe requirement is relaxed, we have
// no knowledge of media segment boundaries here. Now, we log but don't trigger
// decode error, since we allow these sequences which may cause extra decoder
// work or other side-effects.
const int kMaxStrangeSameTimestampsLogs = 20;
// Helper method that returns true if |ranges| is sorted in increasing order,
// false otherwise.
bool IsRangeListSorted(const std::list<media::SourceBufferRange*>& ranges) {
DecodeTimestamp prev = kNoDecodeTimestamp();
for (std::list<SourceBufferRange*>::const_iterator itr = ranges.begin();
itr != ranges.end(); ++itr) {
if (prev != kNoDecodeTimestamp() && prev >= (*itr)->GetStartTimestamp())
return false;
prev = (*itr)->GetEndTimestamp();
}
return true;
}
// Returns an estimate of how far from the beginning or end of a range a buffer
// can be to still be considered in the range, given the |approximate_duration|
// of a buffer in the stream.
// TODO: Once all stream parsers emit accurate frame durations, use logic like
// FrameProcessor (2*last_frame_duration + last_decode_timestamp) instead of an
// overall maximum interbuffer delta for range discontinuity detection, and
// adjust similarly for splice frame discontinuity detection.
// See http://crbug.com/351489 and http://crbug.com/351166.
base::TimeDelta ComputeFudgeRoom(base::TimeDelta approximate_duration) {
// Because we do not know exactly when is the next timestamp, any buffer
// that starts within 2x the approximate duration of a buffer is considered
// within this range.
return 2 * approximate_duration;
}
// The amount of time the beginning of the buffered data can differ from the
// start time in order to still be considered the start of stream.
base::TimeDelta kSeekToStartFudgeRoom() {
return base::TimeDelta::FromMilliseconds(1000);
}
// Helper method for logging, converts a range into a readable string.
std::string RangeToString(const SourceBufferRange& range) {
if (range.size_in_bytes() == 0) {
return "[]";
}
std::stringstream ss;
ss << "[" << range.GetStartTimestamp().InSecondsF() << ";"
<< range.GetEndTimestamp().InSecondsF() << "("
<< range.GetBufferedEndTimestamp().InSecondsF() << ")]";
return ss.str();
}
// Helper method for logging, converts a set of ranges into a readable string.
std::string RangesToString(const SourceBufferStream::RangeList& ranges) {
if (ranges.empty()) return "<EMPTY>";
std::stringstream ss;
for (SourceBufferStream::RangeList::const_iterator iter = ranges.begin();
iter != ranges.end(); ++iter) {
if (iter != ranges.begin()) ss << " ";
ss << RangeToString(**iter);
}
return ss.str();
}
std::string BufferQueueToLogString(
const SourceBufferStream::BufferQueue& buffers) {
std::stringstream result;
if (buffers.front()->GetDecodeTimestamp().InMicroseconds() ==
buffers.front()->timestamp().InMicroseconds() &&
buffers.back()->GetDecodeTimestamp().InMicroseconds() ==
buffers.back()->timestamp().InMicroseconds()) {
result << "dts/pts=[" << buffers.front()->timestamp().InSecondsF() << ";"
<< buffers.back()->timestamp().InSecondsF()
<< "(last frame dur=" << buffers.back()->duration().InSecondsF()
<< ")]";
} else {
result << "dts=[" << buffers.front()->GetDecodeTimestamp().InSecondsF()
<< ";" << buffers.back()->GetDecodeTimestamp().InSecondsF()
<< "] pts=[" << buffers.front()->timestamp().InSecondsF() << ";"
<< buffers.back()->timestamp().InSecondsF()
<< "(last frame dur=" << buffers.back()->duration().InSecondsF()
<< ")]";
}
return result.str();
}
SourceBufferRange::GapPolicy TypeToGapPolicy(SourceBufferStream::Type type) {
switch (type) {
case SourceBufferStream::kAudio:
case SourceBufferStream::kVideo:
return SourceBufferRange::NO_GAPS_ALLOWED;
case SourceBufferStream::kText:
return SourceBufferRange::ALLOW_GAPS;
}
NOTREACHED();
return SourceBufferRange::NO_GAPS_ALLOWED;
}
} // namespace
SourceBufferStream::SourceBufferStream(const AudioDecoderConfig& audio_config,
const scoped_refptr<MediaLog>& media_log,
bool splice_frames_enabled)
: SourceBufferStreamState(splice_frames_enabled),
media_log_(media_log),
seek_buffer_timestamp_(kNoTimestamp),
coded_frame_group_start_time_(kNoDecodeTimestamp()),
range_for_next_append_(ranges_.end()),
last_output_buffer_timestamp_(kNoDecodeTimestamp()),
max_interbuffer_distance_(kNoTimestamp),
memory_limit_(COBALT_MEDIA_BUFFER_NON_VIDEO_BUDGET) {
DCHECK(audio_config.IsValidConfig());
audio_configs_.push_back(audio_config);
}
SourceBufferStream::SourceBufferStream(const VideoDecoderConfig& video_config,
const scoped_refptr<MediaLog>& media_log,
bool splice_frames_enabled)
: SourceBufferStreamState(splice_frames_enabled),
media_log_(media_log),
seek_buffer_timestamp_(kNoTimestamp),
coded_frame_group_start_time_(kNoDecodeTimestamp()),
range_for_next_append_(ranges_.end()),
last_output_buffer_timestamp_(kNoDecodeTimestamp()),
max_interbuffer_distance_(kNoTimestamp) {
DCHECK(video_config.IsValidConfig());
video_configs_.push_back(video_config);
VideoResolution resolution =
GetVideoResolution(video_config.visible_rect().size());
memory_limit_ = resolution <= kVideoResolution1080p
? COBALT_MEDIA_BUFFER_VIDEO_BUDGET_1080P
: COBALT_MEDIA_BUFFER_VIDEO_BUDGET_4K;
}
SourceBufferStream::SourceBufferStream(const TextTrackConfig& text_config,
const scoped_refptr<MediaLog>& media_log,
bool splice_frames_enabled)
: SourceBufferStreamState(splice_frames_enabled),
media_log_(media_log),
text_track_config_(text_config),
seek_buffer_timestamp_(kNoTimestamp),
coded_frame_group_start_time_(kNoDecodeTimestamp()),
range_for_next_append_(ranges_.end()),
last_output_buffer_timestamp_(kNoDecodeTimestamp()),
max_interbuffer_distance_(kNoTimestamp),
memory_limit_(COBALT_MEDIA_BUFFER_NON_VIDEO_BUDGET) {}
SourceBufferStream::~SourceBufferStream() {
while (!ranges_.empty()) {
delete ranges_.front();
ranges_.pop_front();
}
}
void SourceBufferStream::OnStartOfCodedFrameGroup(
DecodeTimestamp coded_frame_group_start_time) {
DVLOG(1) << __func__ << " " << GetStreamTypeName() << " ("
<< coded_frame_group_start_time.InSecondsF() << ")";
DCHECK(!end_of_stream_);
coded_frame_group_start_time_ = coded_frame_group_start_time;
new_coded_frame_group_ = true;
RangeList::iterator last_range = range_for_next_append_;
range_for_next_append_ = FindExistingRangeFor(coded_frame_group_start_time);
// Only reset |last_appended_buffer_timestamp_| if this new coded frame group
// is not adjacent to the previous coded frame group appended to the stream.
if (range_for_next_append_ == ranges_.end() ||
!AreAdjacentInSequence(last_appended_buffer_timestamp_,
coded_frame_group_start_time)) {
ResetLastAppendedState();
DVLOG(3) << __func__ << " next appended buffers will "
<< (range_for_next_append_ == ranges_.end()
? "be in a new range"
: "overlap an existing range");
} else if (last_range != ranges_.end()) {
DCHECK(last_range == range_for_next_append_);
DVLOG(3) << __func__ << " next appended buffers will continue range unless "
<< "intervening remove makes discontinuity";
}
}
bool SourceBufferStream::Append(const BufferQueue& buffers) {
TRACE_EVENT2("media", "SourceBufferStream::Append", "stream type",
GetStreamTypeName(), "buffers to append", buffers.size());
DCHECK(!buffers.empty());
DCHECK(coded_frame_group_start_time_ != kNoDecodeTimestamp());
DCHECK(coded_frame_group_start_time_ <=
buffers.front()->GetDecodeTimestamp());
DCHECK(!end_of_stream_);
DVLOG(1) << __func__ << " " << GetStreamTypeName() << ": buffers "
<< BufferQueueToLogString(buffers);
// New coded frame groups emitted by the coded frame processor must begin with
// a keyframe. TODO(wolenetz): Change this to [DCHECK + MEDIA_LOG(ERROR...) +
// return false] once the CHECK has baked in a stable release. See
// https://crbug.com/580621.
CHECK(!new_coded_frame_group_ || buffers.front()->is_key_frame());
// Buffers within a coded frame group should be monotonically increasing.
if (!IsMonotonicallyIncreasing(buffers)) {
return false;
}
if (coded_frame_group_start_time_ < DecodeTimestamp() ||
buffers.front()->GetDecodeTimestamp() < DecodeTimestamp()) {
MEDIA_LOG(ERROR, media_log_)
<< "Cannot append a coded frame group with negative timestamps.";
return false;
}
UpdateMaxInterbufferDistance(buffers);
SetConfigIds(buffers);
// Save a snapshot of stream state before range modifications are made.
DecodeTimestamp next_buffer_timestamp = GetNextBufferTimestamp();
BufferQueue deleted_buffers;
PrepareRangesForNextAppend(buffers, &deleted_buffers);
// If there's a range for |buffers|, insert |buffers| accordingly. Otherwise,
// create a new range with |buffers|.
if (range_for_next_append_ != ranges_.end()) {
if (new_coded_frame_group_ && (!splice_frames_enabled_ ||
buffers.front()->splice_buffers().empty())) {
// If the first append to this stream in a new coded frame group continues
// a previous range, use the new group's start time instead of the first
// new buffer's timestamp as the proof of adjacency to the existing range.
// A large gap (larger than our normal buffer adjacency test) can occur in
// a muxed set of streams (which share a common coded frame group start
// time) with a significantly jagged start across the streams.
// Don't do this logic if there was a splice frame generated for the first
// new buffer, since splices are guaranteed to be in the same range and
// adjacent, and since the splice frame's timestamp can be less than
// |coded_frame_group_start_time_| due to the splicing.
(*range_for_next_append_)
->AppendBuffersToEnd(buffers, coded_frame_group_start_time_);
} else {
// Otherwise, use the first new buffer's timestamp as the proof of
// adjacency.
(*range_for_next_append_)
->AppendBuffersToEnd(buffers, kNoDecodeTimestamp());
}
last_appended_buffer_timestamp_ = buffers.back()->GetDecodeTimestamp();
last_appended_buffer_duration_ = buffers.back()->duration();
last_appended_buffer_is_keyframe_ = buffers.back()->is_key_frame();
} else {
DecodeTimestamp new_range_start_time = std::min(
coded_frame_group_start_time_, buffers.front()->GetDecodeTimestamp());
const BufferQueue* buffers_for_new_range = &buffers;
BufferQueue trimmed_buffers;
// If the new range is not being created because of a new coded frame group,
// then we must make sure that we start with a key frame. This can happen
// if the GOP in the previous append gets destroyed by a Remove() call.
if (!new_coded_frame_group_) {
BufferQueue::const_iterator itr = buffers.begin();
// Scan past all the non-key-frames.
while (itr != buffers.end() && !(*itr)->is_key_frame()) {
++itr;
}
// If we didn't find a key frame, then update the last appended
// buffer state and return.
if (itr == buffers.end()) {
last_appended_buffer_timestamp_ = buffers.back()->GetDecodeTimestamp();
last_appended_buffer_duration_ = buffers.back()->duration();
last_appended_buffer_is_keyframe_ = buffers.back()->is_key_frame();
DVLOG(1) << __func__ << " " << GetStreamTypeName()
<< ": new buffers in the middle of coded frame group depend on"
"keyframe that has been removed, and contain no keyframes."
"Skipping further processing.";
DVLOG(1) << __func__ << " " << GetStreamTypeName()
<< ": done. ranges_=" << RangesToString(ranges_);
return true;
} else if (itr != buffers.begin()) {
// Copy the first key frame and everything after it into
// |trimmed_buffers|.
trimmed_buffers.assign(itr, buffers.end());
buffers_for_new_range = &trimmed_buffers;
}
new_range_start_time =
buffers_for_new_range->front()->GetDecodeTimestamp();
}
range_for_next_append_ = AddToRanges(new SourceBufferRange(
TypeToGapPolicy(GetType()), *buffers_for_new_range,
new_range_start_time,
base::Bind(&SourceBufferStream::GetMaxInterbufferDistance,
base::Unretained(this))));
last_appended_buffer_timestamp_ =
buffers_for_new_range->back()->GetDecodeTimestamp();
last_appended_buffer_duration_ = buffers_for_new_range->back()->duration();
last_appended_buffer_is_keyframe_ =
buffers_for_new_range->back()->is_key_frame();
}
new_coded_frame_group_ = false;
MergeWithAdjacentRangeIfNecessary(range_for_next_append_);
// Seek to try to fulfill a previous call to Seek().
if (seek_pending_) {
DCHECK(!selected_range_);
DCHECK(deleted_buffers.empty());
Seek(seek_buffer_timestamp_);
}
if (!deleted_buffers.empty()) {
DecodeTimestamp start_of_deleted =
deleted_buffers.front()->GetDecodeTimestamp();
DCHECK(track_buffer_.empty() ||
track_buffer_.back()->GetDecodeTimestamp() < start_of_deleted)
<< "decode timestamp "
<< track_buffer_.back()->GetDecodeTimestamp().InSecondsF() << " sec"
<< ", start_of_deleted " << start_of_deleted.InSecondsF() << " sec";
track_buffer_.insert(track_buffer_.end(), deleted_buffers.begin(),
deleted_buffers.end());
DVLOG(3) << __func__ << " " << GetStreamTypeName() << " Added "
<< deleted_buffers.size()
<< " buffers to track buffer. TB size is now "
<< track_buffer_.size();
} else {
DVLOG(3) << __func__ << " " << GetStreamTypeName()
<< " No deleted buffers for track buffer";
}
// Prune any extra buffers in |track_buffer_| if new keyframes
// are appended to the range covered by |track_buffer_|.
if (!track_buffer_.empty()) {
DecodeTimestamp keyframe_timestamp =
FindKeyframeAfterTimestamp(track_buffer_.front()->GetDecodeTimestamp());
if (keyframe_timestamp != kNoDecodeTimestamp())
PruneTrackBuffer(keyframe_timestamp);
}
SetSelectedRangeIfNeeded(next_buffer_timestamp);
DVLOG(1) << __func__ << " " << GetStreamTypeName()
<< ": done. ranges_=" << RangesToString(ranges_);
// TODO: Investigate if the following DCHECK should be restored.
// DCHECK(IsRangeListSorted(ranges_));
DCHECK(OnlySelectedRangeIsSeeked());
return true;
}
void SourceBufferStream::Remove(base::TimeDelta start, base::TimeDelta end,
base::TimeDelta duration) {
DVLOG(1) << __func__ << " " << GetStreamTypeName() << " ("
<< start.InSecondsF() << ", " << end.InSecondsF() << ", "
<< duration.InSecondsF() << ")";
DCHECK(start >= base::TimeDelta()) << start.InSecondsF();
DCHECK(start < end) << "start " << start.InSecondsF() << " end "
<< end.InSecondsF();
DCHECK(duration != kNoTimestamp);
DecodeTimestamp start_dts = DecodeTimestamp::FromPresentationTime(start);
DecodeTimestamp end_dts = DecodeTimestamp::FromPresentationTime(end);
DecodeTimestamp remove_end_timestamp =
DecodeTimestamp::FromPresentationTime(duration);
DecodeTimestamp keyframe_timestamp = FindKeyframeAfterTimestamp(end_dts);
if (keyframe_timestamp != kNoDecodeTimestamp()) {
remove_end_timestamp = keyframe_timestamp;
} else if (end_dts < remove_end_timestamp) {
remove_end_timestamp = end_dts;
}
BufferQueue deleted_buffers;
RemoveInternal(start_dts, remove_end_timestamp, false, &deleted_buffers);
if (!deleted_buffers.empty()) {
// Buffers for the current position have been removed.
SetSelectedRangeIfNeeded(deleted_buffers.front()->GetDecodeTimestamp());
if (last_output_buffer_timestamp_ == kNoDecodeTimestamp()) {
// We just removed buffers for the current playback position for this
// stream, yet we also had output no buffer since the last Seek.
// Re-seek to prevent stall.
DVLOG(1) << __func__ << " " << GetStreamTypeName() << ": re-seeking to "
<< seek_buffer_timestamp_
<< " to prevent stall if this time becomes buffered again";
Seek(seek_buffer_timestamp_);
}
}
}
DecodeTimestamp SourceBufferStream::PotentialNextAppendTimestamp() const {
// The next potential append will either be just at or after
// |last_appended_buffer_timestamp_| (if known), or if unknown and we are
// still at the beginning of a new coded frame group, then will be into the
// range (if any) to which |coded_frame_group_start_time_| belongs.
if (last_appended_buffer_timestamp_ != kNoDecodeTimestamp()) {
// TODO(wolenetz): Determine if this +1us is still necessary. See
// https://crbug.com/589295.
return last_appended_buffer_timestamp_ +
base::TimeDelta::FromInternalValue(1);
}
if (new_coded_frame_group_) return coded_frame_group_start_time_;
// If we still don't know a potential next append timestamp, then we have
// removed the ranged to which it previously belonged and have not completed a
// subsequent append or received a subsequent OnStartOfCodedFrameGroup()
// signal.
return kNoDecodeTimestamp();
}
void SourceBufferStream::UpdateLastAppendStateForRemove(
DecodeTimestamp remove_start, DecodeTimestamp remove_end,
bool exclude_start) {
// TODO(chcunningham): change exclude_start to include_start in this class and
// SourceBufferRange. Negatives are hard to reason about.
bool include_start = !exclude_start;
// No need to check previous append's GOP if starting a new CFG. New CFG is
// already required to begin with a key frame.
if (new_coded_frame_group_) return;
if (range_for_next_append_ != ranges_.end()) {
if (last_appended_buffer_timestamp_ != kNoDecodeTimestamp()) {
DCHECK((*range_for_next_append_)
->BelongsToRange(last_appended_buffer_timestamp_));
// Note start and end of last appended GOP.
DecodeTimestamp gop_end = last_appended_buffer_timestamp_;
DecodeTimestamp gop_start =
(*range_for_next_append_)->KeyframeBeforeTimestamp(gop_end);
// If last append is about to be disrupted, reset associated state so we
// know to create a new range for future appends and require an initial
// key frame.
if (((include_start && remove_start == gop_end) ||
remove_start < gop_end) &&
remove_end > gop_start) {
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< " Resetting next append state for remove ("
<< remove_start.InSecondsF() << ", " << remove_end.InSecondsF()
<< ", " << exclude_start << ")";
range_for_next_append_ = ranges_.end();
ResetLastAppendedState();
}
} else {
NOTREACHED() << __func__ << " " << GetStreamTypeName()
<< " range_for_next_append_ set, but not tracking last"
<< " append nor new coded frame group.";
}
}
}
void SourceBufferStream::RemoveInternal(DecodeTimestamp start,
DecodeTimestamp end, bool exclude_start,
BufferQueue* deleted_buffers) {
DVLOG(2) << __func__ << " " << GetStreamTypeName() << " ("
<< start.InSecondsF() << ", " << end.InSecondsF() << ", "
<< exclude_start << ")";
DVLOG(3) << __func__ << " " << GetStreamTypeName()
<< ": before remove ranges_=" << RangesToString(ranges_);
DCHECK(start >= DecodeTimestamp());
DCHECK(start < end) << "start " << start.InSecondsF() << " end "
<< end.InSecondsF();
DCHECK(deleted_buffers);
// Doing this upfront simplifies decisions about range_for_next_append_ below.
UpdateLastAppendStateForRemove(start, end, exclude_start);
RangeList::iterator itr = ranges_.begin();
while (itr != ranges_.end()) {
SourceBufferRange* range = *itr;
if (range->GetStartTimestamp() >= end) break;
// Split off any remaining GOPs starting at or after |end| and add it to
// |ranges_|.
SourceBufferRange* new_range = range->SplitRange(end);
if (new_range) {
itr = ranges_.insert(++itr, new_range);
// Update |range_for_next_append_| if it was previously |range| and should
// be |new_range| now.
if (range_for_next_append_ != ranges_.end() &&
*range_for_next_append_ == range) {
DecodeTimestamp potential_next_append_timestamp =
PotentialNextAppendTimestamp();
if (potential_next_append_timestamp != kNoDecodeTimestamp() &&
new_range->BelongsToRange(potential_next_append_timestamp)) {
range_for_next_append_ = itr;
}
}
--itr;
// Update the selected range if the next buffer position was transferred
// to |new_range|.
if (new_range->HasNextBufferPosition()) SetSelectedRange(new_range);
}
// Truncate the current range so that it only contains data before
// the removal range.
BufferQueue saved_buffers;
bool delete_range = range->TruncateAt(start, &saved_buffers, exclude_start);
// Check to see if the current playback position was removed and
// update the selected range appropriately.
if (!saved_buffers.empty()) {
DCHECK(!range->HasNextBufferPosition());
DCHECK(deleted_buffers->empty());
*deleted_buffers = saved_buffers;
}
if (range == selected_range_ && !range->HasNextBufferPosition())
SetSelectedRange(NULL);
// If the current range now is completely covered by the removal
// range then delete it and move on.
if (delete_range) {
DeleteAndRemoveRange(&itr);
continue;
}
// Clear |range_for_next_append_| if we determine that the removal
// operation makes it impossible for the next append to be added
// to the current range.
if (range_for_next_append_ != ranges_.end() &&
*range_for_next_append_ == range) {
DecodeTimestamp potential_next_append_timestamp =
PotentialNextAppendTimestamp();
if (!range->BelongsToRange(potential_next_append_timestamp)) {
DVLOG(1) << "Resetting range_for_next_append_ since the next append"
<< " can't add to the current range.";
range_for_next_append_ =
FindExistingRangeFor(potential_next_append_timestamp);
}
}
// Move on to the next range.
++itr;
}
DVLOG(3) << __func__ << " " << GetStreamTypeName()
<< ": after remove ranges_=" << RangesToString(ranges_);
DCHECK(IsRangeListSorted(ranges_));
DCHECK(OnlySelectedRangeIsSeeked());
}
void SourceBufferStream::ResetSeekState() {
SetSelectedRange(NULL);
track_buffer_.clear();
config_change_pending_ = false;
last_output_buffer_timestamp_ = kNoDecodeTimestamp();
just_exhausted_track_buffer_ = false;
splice_buffers_index_ = 0;
pending_buffer_ = NULL;
pending_buffers_complete_ = false;
}
void SourceBufferStream::ResetLastAppendedState() {
last_appended_buffer_timestamp_ = kNoDecodeTimestamp();
last_appended_buffer_duration_ = kNoTimestamp;
last_appended_buffer_is_keyframe_ = false;
}
bool SourceBufferStream::ShouldSeekToStartOfBuffered(
base::TimeDelta seek_timestamp) const {
if (ranges_.empty()) return false;
base::TimeDelta beginning_of_buffered =
ranges_.front()->GetStartTimestamp().ToPresentationTime();
return (seek_timestamp <= beginning_of_buffered &&
beginning_of_buffered < kSeekToStartFudgeRoom());
}
bool SourceBufferStream::IsMonotonicallyIncreasing(const BufferQueue& buffers) {
DCHECK(!buffers.empty());
DecodeTimestamp prev_timestamp = last_appended_buffer_timestamp_;
bool prev_is_keyframe = last_appended_buffer_is_keyframe_;
for (BufferQueue::const_iterator itr = buffers.begin(); itr != buffers.end();
++itr) {
DecodeTimestamp current_timestamp = (*itr)->GetDecodeTimestamp();
bool current_is_keyframe = (*itr)->is_key_frame();
DCHECK(current_timestamp != kNoDecodeTimestamp());
DCHECK((*itr)->duration() >= base::TimeDelta())
<< "Packet with invalid duration."
<< " pts " << (*itr)->timestamp().InSecondsF() << " dts "
<< (*itr)->GetDecodeTimestamp().InSecondsF() << " dur "
<< (*itr)->duration().InSecondsF();
if (prev_timestamp != kNoDecodeTimestamp()) {
if (current_timestamp < prev_timestamp) {
MEDIA_LOG(ERROR, media_log_)
<< "Buffers did not monotonically increase.";
return false;
}
if (current_timestamp == prev_timestamp &&
SourceBufferRange::IsUncommonSameTimestampSequence(
prev_is_keyframe, current_is_keyframe)) {
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_strange_same_timestamps_logs_,
kMaxStrangeSameTimestampsLogs)
<< "Detected an append sequence with keyframe following a "
"non-keyframe, both with the same decode timestamp of "
<< current_timestamp.InSecondsF();
}
}
prev_timestamp = current_timestamp;
prev_is_keyframe = current_is_keyframe;
}
return true;
}
bool SourceBufferStream::OnlySelectedRangeIsSeeked() const {
for (RangeList::const_iterator itr = ranges_.begin(); itr != ranges_.end();
++itr) {
if ((*itr)->HasNextBufferPosition() && (*itr) != selected_range_)
return false;
}
return !selected_range_ || selected_range_->HasNextBufferPosition();
}
void SourceBufferStream::UpdateMaxInterbufferDistance(
const BufferQueue& buffers) {
DCHECK(!buffers.empty());
DecodeTimestamp prev_timestamp = last_appended_buffer_timestamp_;
for (BufferQueue::const_iterator itr = buffers.begin(); itr != buffers.end();
++itr) {
DecodeTimestamp current_timestamp = (*itr)->GetDecodeTimestamp();
DCHECK(current_timestamp != kNoDecodeTimestamp());
base::TimeDelta interbuffer_distance = (*itr)->duration();
DCHECK(interbuffer_distance >= base::TimeDelta());
if (prev_timestamp != kNoDecodeTimestamp()) {
interbuffer_distance =
std::max(current_timestamp - prev_timestamp, interbuffer_distance);
}
if (interbuffer_distance > base::TimeDelta()) {
if (max_interbuffer_distance_ == kNoTimestamp) {
max_interbuffer_distance_ = interbuffer_distance;
} else {
max_interbuffer_distance_ =
std::max(max_interbuffer_distance_, interbuffer_distance);
}
}
prev_timestamp = current_timestamp;
}
}
void SourceBufferStream::SetConfigIds(const BufferQueue& buffers) {
for (BufferQueue::const_iterator itr = buffers.begin(); itr != buffers.end();
++itr) {
(*itr)->SetConfigId(append_config_index_);
}
}
bool SourceBufferStream::GarbageCollectIfNeeded(DecodeTimestamp media_time,
size_t newDataSize) {
DCHECK(media_time != kNoDecodeTimestamp());
// Garbage collection should only happen before/during appending new data,
// which should not happen in end-of-stream state.
DCHECK(!end_of_stream_);
// Compute size of |ranges_|.
size_t ranges_size = GetBufferedSize();
// Sanity and overflow checks
if ((newDataSize > memory_limit_) ||
(ranges_size + newDataSize < ranges_size)) {
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_garbage_collect_algorithm_logs_,
kMaxGarbageCollectAlgorithmWarningLogs)
<< GetStreamTypeName() << " stream: "
<< "new append of newDataSize=" << newDataSize
<< " bytes exceeds memory_limit_=" << memory_limit_
<< ", currently buffered ranges_size=" << ranges_size;
return false;
}
base::TimeDelta duration = GetBufferedDurationForGarbageCollection();
size_t bytes_to_free = 0;
// Check if we're under or at the memory/duration limit.
const auto kGcDurationThresholdInMilliseconds =
COBALT_MEDIA_SOURCE_GARBAGE_COLLECTION_DURATION_THRESHOLD_IN_SECONDS *
1000;
if (ranges_size + newDataSize > memory_limit_) {
bytes_to_free = ranges_size + newDataSize - memory_limit_;
} else if (duration.InMilliseconds() > kGcDurationThresholdInMilliseconds) {
// Estimate the size to free.
auto duration_to_free =
duration.InMilliseconds() - kGcDurationThresholdInMilliseconds;
bytes_to_free = ranges_size * duration_to_free / duration.InMilliseconds();
}
if (bytes_to_free == 0) {
return true;
}
DCHECK_GT(bytes_to_free, 0);
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< ": Before GC media_time=" << media_time.InSecondsF()
<< " ranges_=" << RangesToString(ranges_)
<< " seek_pending_=" << seek_pending_
<< " ranges_size=" << ranges_size << " newDataSize=" << newDataSize
<< " memory_limit_=" << memory_limit_
<< " last_appended_buffer_timestamp_="
<< last_appended_buffer_timestamp_.InSecondsF();
if (selected_range_ && !seek_pending_ &&
media_time > selected_range_->GetBufferedEndTimestamp()) {
// Strictly speaking |media_time| (taken from HTMLMediaElement::currentTime)
// should always be in the buffered ranges, but media::Pipeline uses audio
// stream as the main time source, when audio is present.
// In cases when audio and video streams have different buffered ranges, the
// |media_time| value might be slightly outside of the video stream buffered
// range. In those cases we need to clamp |media_time| value to the current
// stream buffered ranges, to ensure the MSE garbage collection algorithm
// works correctly (see crbug.com/563292 for details).
DecodeTimestamp selected_buffered_end =
selected_range_->GetBufferedEndTimestamp();
DVLOG(2) << __func__ << " media_time " << media_time.InSecondsF()
<< " is outside of selected_range_=["
<< selected_range_->GetStartTimestamp().InSecondsF() << ";"
<< selected_buffered_end.InSecondsF()
<< "] clamping media_time to be "
<< selected_buffered_end.InSecondsF();
media_time = selected_buffered_end;
}
size_t bytes_freed = 0;
// If last appended buffer position was earlier than the current playback time
// then try deleting data between last append and current media_time.
if (last_appended_buffer_timestamp_ != kNoDecodeTimestamp() &&
last_appended_buffer_duration_ != kNoTimestamp &&
media_time >
last_appended_buffer_timestamp_ + last_appended_buffer_duration_) {
size_t between = FreeBuffersAfterLastAppended(bytes_to_free, media_time);
DVLOG(3) << __func__ << " FreeBuffersAfterLastAppended "
<< " released " << between << " bytes"
<< " ranges_=" << RangesToString(ranges_);
bytes_freed += between;
// Some players start appending data at the new seek target position before
// actually initiating the seek operation (i.e. they try to improve seek
// performance by prebuffering some data at the seek target position and
// initiating seek once enough data is pre-buffered. In those cases we'll
// see that data is being appended at some new position, but there is no
// pending seek reported yet. In this situation we need to try preserving
// the most recently appended data, i.e. data belonging to the same buffered
// range as the most recent append.
if (range_for_next_append_ != ranges_.end()) {
DCHECK((*range_for_next_append_)->GetStartTimestamp() <= media_time);
media_time = (*range_for_next_append_)->GetStartTimestamp();
DVLOG(3) << __func__ << " media_time adjusted to "
<< media_time.InSecondsF();
}
}
// If there is an unsatisfied pending seek, we can safely remove all data that
// is earlier than seek target, then remove from the back until we reach the
// most recently appended GOP and then remove from the front if we still don't
// have enough space for the upcoming append.
if (bytes_freed < bytes_to_free && seek_pending_) {
DCHECK(!ranges_.empty());
// All data earlier than the seek target |media_time| can be removed safely
size_t front = FreeBuffers(bytes_to_free - bytes_freed, media_time, false);
DVLOG(3) << __func__ << " Removed " << front
<< " bytes from the front. ranges_=" << RangesToString(ranges_);
bytes_freed += front;
// If removing data earlier than |media_time| didn't free up enough space,
// then try deleting from the back until we reach most recently appended GOP
if (bytes_freed < bytes_to_free) {
size_t back = FreeBuffers(bytes_to_free - bytes_freed, media_time, true);
DVLOG(3) << __func__ << " Removed " << back
<< " bytes from the back. ranges_=" << RangesToString(ranges_);
bytes_freed += back;
}
// If even that wasn't enough, then try greedily deleting from the front,
// that should allow us to remove as much data as necessary to succeed.
if (bytes_freed < bytes_to_free) {
size_t front2 = FreeBuffers(bytes_to_free - bytes_freed,
ranges_.back()->GetEndTimestamp(), false);
DVLOG(3) << __func__ << " Removed " << front2
<< " bytes from the front. ranges_=" << RangesToString(ranges_);
bytes_freed += front2;
}
DCHECK(bytes_freed >= bytes_to_free);
}
// Try removing data from the front of the SourceBuffer up to |media_time|
// position.
if (bytes_freed < bytes_to_free) {
size_t front = FreeBuffers(bytes_to_free - bytes_freed, media_time, false);
DVLOG(3) << __func__ << " Removed " << front
<< " bytes from the front. ranges_=" << RangesToString(ranges_);
bytes_freed += front;
}
// Try removing data from the back of the SourceBuffer, until we reach the
// most recent append position.
if (bytes_freed < bytes_to_free) {
size_t back = FreeBuffers(bytes_to_free - bytes_freed, media_time, true);
DVLOG(3) << __func__ << " Removed " << back
<< " bytes from the back. ranges_=" << RangesToString(ranges_);
bytes_freed += back;
}
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< ": After GC bytes_to_free=" << bytes_to_free
<< " bytes_freed=" << bytes_freed
<< " ranges_=" << RangesToString(ranges_);
return bytes_freed >= bytes_to_free;
}
size_t SourceBufferStream::FreeBuffersAfterLastAppended(
size_t total_bytes_to_free, DecodeTimestamp media_time) {
DVLOG(4) << __func__ << " last_appended_buffer_timestamp_="
<< last_appended_buffer_timestamp_.InSecondsF()
<< " media_time=" << media_time.InSecondsF();
DecodeTimestamp remove_range_start = last_appended_buffer_timestamp_;
if (last_appended_buffer_is_keyframe_)
remove_range_start += GetMaxInterbufferDistance();
DecodeTimestamp remove_range_start_keyframe =
FindKeyframeAfterTimestamp(remove_range_start);
if (remove_range_start_keyframe != kNoDecodeTimestamp())
remove_range_start = remove_range_start_keyframe;
if (remove_range_start >= media_time) return 0;
DecodeTimestamp remove_range_end;
size_t bytes_freed = GetRemovalRange(remove_range_start, media_time,
total_bytes_to_free, &remove_range_end);
if (bytes_freed > 0) {
DVLOG(4) << __func__ << " removing ["
<< remove_range_start.ToPresentationTime().InSecondsF() << ";"
<< remove_range_end.ToPresentationTime().InSecondsF() << "]";
Remove(remove_range_start.ToPresentationTime(),
remove_range_end.ToPresentationTime(),
media_time.ToPresentationTime());
}
return bytes_freed;
}
size_t SourceBufferStream::GetRemovalRange(
DecodeTimestamp start_timestamp, DecodeTimestamp end_timestamp,
size_t total_bytes_to_free, DecodeTimestamp* removal_end_timestamp) {
DCHECK(start_timestamp >= DecodeTimestamp()) << start_timestamp.InSecondsF();
DCHECK(start_timestamp < end_timestamp)
<< "start " << start_timestamp.InSecondsF() << ", end "
<< end_timestamp.InSecondsF();
size_t bytes_freed = 0;
for (RangeList::iterator itr = ranges_.begin();
itr != ranges_.end() && bytes_freed < total_bytes_to_free; ++itr) {
SourceBufferRange* range = *itr;
if (range->GetStartTimestamp() >= end_timestamp) break;
if (range->GetEndTimestamp() < start_timestamp) continue;
size_t bytes_to_free = total_bytes_to_free - bytes_freed;
size_t bytes_removed = range->GetRemovalGOP(
start_timestamp, end_timestamp, bytes_to_free, removal_end_timestamp);
bytes_freed += bytes_removed;
}
return bytes_freed;
}
size_t SourceBufferStream::FreeBuffers(size_t total_bytes_to_free,
DecodeTimestamp media_time,
bool reverse_direction) {
TRACE_EVENT2("media", "SourceBufferStream::FreeBuffers",
"total bytes to free", total_bytes_to_free, "reverse direction",
reverse_direction);
DCHECK_GT(total_bytes_to_free, 0u);
size_t bytes_freed = 0;
// This range will save the last GOP appended to |range_for_next_append_|
// if the buffers surrounding it get deleted during garbage collection.
SourceBufferRange* new_range_for_append = NULL;
while (!ranges_.empty() && bytes_freed < total_bytes_to_free) {
SourceBufferRange* current_range = NULL;
BufferQueue buffers;
size_t bytes_deleted = 0;
if (reverse_direction) {
current_range = ranges_.back();
DVLOG(5) << "current_range=" << RangeToString(*current_range);
if (current_range->LastGOPContainsNextBufferPosition()) {
DCHECK_EQ(current_range, selected_range_);
DVLOG(5) << "current_range contains next read position, stopping GC";
break;
}
DVLOG(5) << "Deleting GOP from back: " << RangeToString(*current_range);
bytes_deleted = current_range->DeleteGOPFromBack(&buffers);
} else {
current_range = ranges_.front();
DVLOG(5) << "current_range=" << RangeToString(*current_range);
// FirstGOPEarlierThanMediaTime() is useful here especially if
// |seek_pending_| (such that no range contains next buffer
// position).
// FirstGOPContainsNextBufferPosition() is useful here especially if
// |!seek_pending_| to protect against DeleteGOPFromFront() if
// FirstGOPEarlierThanMediaTime() was insufficient alone.
if (!current_range->FirstGOPEarlierThanMediaTime(media_time) ||
current_range->FirstGOPContainsNextBufferPosition()) {
// We have removed all data up to the GOP that contains current playback
// position, we can't delete any further.
DVLOG(5) << "current_range contains playback position, stopping GC";
break;
}
DVLOG(4) << "Deleting GOP from front: " << RangeToString(*current_range)
<< ", media_time: " << media_time.InMicroseconds()
<< ", current_range->HasNextBufferPosition(): "
<< current_range->HasNextBufferPosition();
bytes_deleted = current_range->DeleteGOPFromFront(&buffers);
}
// Check to see if we've just deleted the GOP that was last appended.
DecodeTimestamp end_timestamp = buffers.back()->GetDecodeTimestamp();
if (end_timestamp == last_appended_buffer_timestamp_) {
DCHECK(last_appended_buffer_timestamp_ != kNoDecodeTimestamp());
DCHECK(!new_range_for_append);
// Create a new range containing these buffers.
new_range_for_append = new SourceBufferRange(
TypeToGapPolicy(GetType()), buffers, kNoDecodeTimestamp(),
base::Bind(&SourceBufferStream::GetMaxInterbufferDistance,
base::Unretained(this)));
range_for_next_append_ = ranges_.end();
} else {
bytes_freed += bytes_deleted;
}
if (current_range->size_in_bytes() == 0) {
DCHECK_NE(current_range, selected_range_);
DCHECK(range_for_next_append_ == ranges_.end() ||
*range_for_next_append_ != current_range);
delete current_range;
reverse_direction ? ranges_.pop_back() : ranges_.pop_front();
}
if (reverse_direction && new_range_for_append) {
// We don't want to delete any further, or we'll be creating gaps
break;
}
}
// Insert |new_range_for_append| into |ranges_|, if applicable.
if (new_range_for_append) {
range_for_next_append_ = AddToRanges(new_range_for_append);
DCHECK(range_for_next_append_ != ranges_.end());
// Check to see if we need to merge |new_range_for_append| with the range
// before or after it. |new_range_for_append| is created whenever the last
// GOP appended is encountered, regardless of whether any buffers after it
// are ultimately deleted. Merging is necessary if there were no buffers
// (or very few buffers) deleted after creating |new_range_for_append|.
if (range_for_next_append_ != ranges_.begin()) {
RangeList::iterator range_before_next = range_for_next_append_;
--range_before_next;
MergeWithAdjacentRangeIfNecessary(range_before_next);
}
MergeWithAdjacentRangeIfNecessary(range_for_next_append_);
}
return bytes_freed;
}
void SourceBufferStream::PrepareRangesForNextAppend(
const BufferQueue& new_buffers, BufferQueue* deleted_buffers) {
DCHECK(deleted_buffers);
// Handle splices between the existing buffers and the new buffers. If a
// splice is generated the timestamp and duration of the first buffer in
// |new_buffers| will be modified.
if (splice_frames_enabled_) GenerateSpliceFrame(new_buffers);
DecodeTimestamp prev_timestamp = last_appended_buffer_timestamp_;
DecodeTimestamp next_timestamp = new_buffers.front()->GetDecodeTimestamp();
if (prev_timestamp != kNoDecodeTimestamp() &&
prev_timestamp != next_timestamp) {
// Clean up the old buffers between the last appended buffer and the
// beginning of |new_buffers|.
RemoveInternal(prev_timestamp, next_timestamp, true, deleted_buffers);
}
// Always make the start of the delete range exclusive for same timestamp
// across the last buffer in the previous append and the first buffer in the
// current append. Never be exclusive if a splice frame was generated because
// we don't generate splice frames for same timestamp situations.
DCHECK(new_buffers.front()->splice_timestamp() !=
new_buffers.front()->timestamp());
const bool exclude_start = new_buffers.front()->splice_buffers().empty() &&
prev_timestamp == next_timestamp;
// Delete the buffers that |new_buffers| overlaps.
DecodeTimestamp start = new_buffers.front()->GetDecodeTimestamp();
if (new_coded_frame_group_) {
// Extend the deletion range earlier to the coded frame group start time if
// this is the first append in a new coded frame group. Note that |start|
// could already be less than |coded_frame_group_start_time_| if a splice
// was generated.
DCHECK(coded_frame_group_start_time_ != kNoDecodeTimestamp());
start = std::min(coded_frame_group_start_time_, start);
}
DecodeTimestamp end = new_buffers.back()->GetDecodeTimestamp();
base::TimeDelta duration = new_buffers.back()->duration();
// Set end time for remove to include the duration of last buffer. If the
// duration is estimated, use 1 microsecond instead to ensure frames are not
// accidentally removed due to over-estimation.
if (duration != kNoTimestamp && duration > base::TimeDelta() &&
!new_buffers.back()->is_duration_estimated()) {
end += duration;
} else {
// TODO(chcunningham): Emit warning when 0ms durations are not expected.
// http://crbug.com/312836
end += base::TimeDelta::FromInternalValue(1);
}
RemoveInternal(start, end, exclude_start, deleted_buffers);
}
bool SourceBufferStream::AreAdjacentInSequence(
DecodeTimestamp first_timestamp, DecodeTimestamp second_timestamp) const {
return first_timestamp < second_timestamp &&
second_timestamp <=
first_timestamp + ComputeFudgeRoom(GetMaxInterbufferDistance());
}
void SourceBufferStream::PruneTrackBuffer(const DecodeTimestamp timestamp) {
// If we don't have the next timestamp, we don't have anything to delete.
if (timestamp == kNoDecodeTimestamp()) return;
while (!track_buffer_.empty() &&
track_buffer_.back()->GetDecodeTimestamp() >= timestamp) {
track_buffer_.pop_back();
}
DVLOG(3) << __func__ << " " << GetStreamTypeName()
<< " Removed all buffers with DTS >= " << timestamp.InSecondsF()
<< ". New track buffer size:" << track_buffer_.size();
}
void SourceBufferStream::MergeWithAdjacentRangeIfNecessary(
const RangeList::iterator& range_with_new_buffers_itr) {
DCHECK(range_with_new_buffers_itr != ranges_.end());
SourceBufferRange* range_with_new_buffers = *range_with_new_buffers_itr;
RangeList::iterator next_range_itr = range_with_new_buffers_itr;
++next_range_itr;
if (next_range_itr == ranges_.end() ||
!range_with_new_buffers->CanAppendRangeToEnd(**next_range_itr)) {
return;
}
bool transfer_current_position = selected_range_ == *next_range_itr;
DVLOG(3) << __func__ << " " << GetStreamTypeName() << " merging "
<< RangeToString(*range_with_new_buffers) << " into "
<< RangeToString(**next_range_itr);
range_with_new_buffers->AppendRangeToEnd(**next_range_itr,
transfer_current_position);
// Update |selected_range_| pointer if |range| has become selected after
// merges.
if (transfer_current_position) SetSelectedRange(range_with_new_buffers);
if (next_range_itr == range_for_next_append_)
range_for_next_append_ = range_with_new_buffers_itr;
DeleteAndRemoveRange(&next_range_itr);
}
void SourceBufferStream::Seek(base::TimeDelta timestamp) {
DCHECK(timestamp >= base::TimeDelta());
DVLOG(1) << __func__ << " " << GetStreamTypeName() << " ("
<< timestamp.InSecondsF() << ")";
ResetSeekState();
seek_buffer_timestamp_ = timestamp;
seek_pending_ = true;
if (ShouldSeekToStartOfBuffered(timestamp)) {
ranges_.front()->SeekToStart();
SetSelectedRange(ranges_.front());
seek_pending_ = false;
seek_buffer_timestamp_ = GetNextBufferTimestamp().ToPresentationTime();
return;
}
DecodeTimestamp seek_dts = DecodeTimestamp::FromPresentationTime(timestamp);
RangeList::iterator itr = ranges_.end();
for (itr = ranges_.begin(); itr != ranges_.end(); ++itr) {
if ((*itr)->CanSeekTo(seek_dts)) break;
}
if (itr == ranges_.end()) return;
SeekAndSetSelectedRange(*itr, seek_dts);
seek_pending_ = false;
seek_buffer_timestamp_ = GetNextBufferTimestamp().ToPresentationTime();
}
bool SourceBufferStream::IsSeekPending() const {
return seek_pending_ && !IsEndOfStreamReached();
}
base::TimeDelta SourceBufferStream::GetSeekKeyframeTimestamp() const {
DCHECK(!IsSeekPending());
return seek_buffer_timestamp_;
}
void SourceBufferStream::OnSetDuration(base::TimeDelta duration) {
DVLOG(1) << __func__ << " " << GetStreamTypeName() << " ("
<< duration.InSecondsF() << ")";
DCHECK(!end_of_stream_);
if (ranges_.empty()) return;
DecodeTimestamp start = DecodeTimestamp::FromPresentationTime(duration);
DecodeTimestamp end = ranges_.back()->GetBufferedEndTimestamp();
// Trim the end if it exceeds the new duration.
if (start < end) {
BufferQueue deleted_buffers;
RemoveInternal(start, end, false, &deleted_buffers);
if (!deleted_buffers.empty()) {
// Truncation removed current position. Clear selected range.
SetSelectedRange(NULL);
}
}
}
SourceBufferStream::Status SourceBufferStream::GetNextBuffer(
scoped_refptr<StreamParserBuffer>* out_buffer) {
DVLOG(2) << __func__ << " " << GetStreamTypeName();
if (!pending_buffer_.get()) {
const SourceBufferStream::Status status = GetNextBufferInternal(out_buffer);
if (status != SourceBufferStream::kSuccess ||
!SetPendingBuffer(out_buffer)) {
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< ": no pending buffer, returning status " << status;
return status;
}
}
if (!pending_buffer_->splice_buffers().empty()) {
const SourceBufferStream::Status status =
HandleNextBufferWithSplice(out_buffer);
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< ": handled next buffer with splice, returning status "
<< status;
return status;
}
DCHECK(pending_buffer_->preroll_buffer().get());
const SourceBufferStream::Status status =
HandleNextBufferWithPreroll(out_buffer);
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< ": handled next buffer with preroll, returning status " << status;
return status;
}
SourceBufferStream::Status SourceBufferStream::HandleNextBufferWithSplice(
scoped_refptr<StreamParserBuffer>* out_buffer) {
const BufferQueue& splice_buffers = pending_buffer_->splice_buffers();
const size_t last_splice_buffer_index = splice_buffers.size() - 1;
// Are there any splice buffers left to hand out? The last buffer should be
// handed out separately since it represents the first post-splice buffer.
if (splice_buffers_index_ < last_splice_buffer_index) {
// Account for config changes which occur between fade out buffers.
if (current_config_index_ !=
splice_buffers[splice_buffers_index_]->GetConfigId()) {
config_change_pending_ = true;
DVLOG(1) << "Config change (splice buffer config ID does not match).";
return SourceBufferStream::kConfigChange;
}
// Every pre splice buffer must have the same splice_timestamp().
DCHECK(pending_buffer_->splice_timestamp() ==
splice_buffers[splice_buffers_index_]->splice_timestamp());
// No pre splice buffers should have preroll.
DCHECK(!splice_buffers[splice_buffers_index_]->preroll_buffer().get());
*out_buffer = splice_buffers[splice_buffers_index_++];
return SourceBufferStream::kSuccess;
}
// Did we hand out the last pre-splice buffer on the previous call?
if (!pending_buffers_complete_) {
DCHECK_EQ(splice_buffers_index_, last_splice_buffer_index);
pending_buffers_complete_ = true;
config_change_pending_ = true;
DVLOG(1) << "Config change (forced for fade in of splice frame).";
return SourceBufferStream::kConfigChange;
}
// All pre-splice buffers have been handed out and a config change completed,
// so hand out the final buffer for fade in. Because a config change is
// always issued prior to handing out this buffer, any changes in config id
// have been inherently handled.
DCHECK(pending_buffers_complete_);
DCHECK_EQ(splice_buffers_index_, splice_buffers.size() - 1);
DCHECK(splice_buffers.back()->splice_timestamp() == kNoTimestamp);
*out_buffer = splice_buffers.back();
pending_buffer_ = NULL;
// If the last splice buffer has preroll, hand off to the preroll handler.
return SetPendingBuffer(out_buffer) ? HandleNextBufferWithPreroll(out_buffer)
: SourceBufferStream::kSuccess;
}
SourceBufferStream::Status SourceBufferStream::HandleNextBufferWithPreroll(
scoped_refptr<StreamParserBuffer>* out_buffer) {
// Any config change should have already been handled.
DCHECK_EQ(current_config_index_, pending_buffer_->GetConfigId());
// Check if the preroll buffer has already been handed out.
if (!pending_buffers_complete_) {
pending_buffers_complete_ = true;
*out_buffer = pending_buffer_->preroll_buffer();
return SourceBufferStream::kSuccess;
}
// Preroll complete, hand out the final buffer.
*out_buffer = pending_buffer_;
pending_buffer_ = NULL;
return SourceBufferStream::kSuccess;
}
SourceBufferStream::Status SourceBufferStream::GetNextBufferInternal(
scoped_refptr<StreamParserBuffer>* out_buffer) {
CHECK(!config_change_pending_);
if (!track_buffer_.empty()) {
DCHECK(!selected_range_);
scoped_refptr<StreamParserBuffer>& next_buffer = track_buffer_.front();
// If the next buffer is an audio splice frame, the next effective config id
// comes from the first splice buffer.
if (next_buffer->GetSpliceBufferConfigId(0) != current_config_index_) {
config_change_pending_ = true;
DVLOG(1) << "Config change (track buffer config ID does not match).";
return kConfigChange;
}
DVLOG(3) << __func__ << " Next buffer coming from track_buffer_";
*out_buffer = next_buffer;
track_buffer_.pop_front();
WarnIfTrackBufferExhaustionSkipsForward(*out_buffer);
last_output_buffer_timestamp_ = (*out_buffer)->GetDecodeTimestamp();
// If the track buffer becomes empty, then try to set the selected range
// based on the timestamp of this buffer being returned.
if (track_buffer_.empty()) {
just_exhausted_track_buffer_ = true;
SetSelectedRangeIfNeeded(last_output_buffer_timestamp_);
}
return kSuccess;
}
DCHECK(track_buffer_.empty());
if (!selected_range_ || !selected_range_->HasNextBuffer()) {
if (IsEndOfStreamReached()) {
return kEndOfStream;
}
DVLOG(3) << __func__ << " " << GetStreamTypeName()
<< ": returning kNeedBuffer "
<< (selected_range_ ? "(selected range has no next buffer)"
: "(no selected range)");
return kNeedBuffer;
}
if (selected_range_->GetNextConfigId() != current_config_index_) {
config_change_pending_ = true;
DVLOG(1) << "Config change (selected range config ID does not match).";
return kConfigChange;
}
CHECK(selected_range_->GetNextBuffer(out_buffer));
WarnIfTrackBufferExhaustionSkipsForward(*out_buffer);
last_output_buffer_timestamp_ = (*out_buffer)->GetDecodeTimestamp();
return kSuccess;
}
void SourceBufferStream::WarnIfTrackBufferExhaustionSkipsForward(
const scoped_refptr<StreamParserBuffer>& next_buffer) {
if (!just_exhausted_track_buffer_) return;
just_exhausted_track_buffer_ = false;
DCHECK(next_buffer->is_key_frame());
DecodeTimestamp next_output_buffer_timestamp =
next_buffer->GetDecodeTimestamp();
base::TimeDelta delta =
next_output_buffer_timestamp - last_output_buffer_timestamp_;
DCHECK_GE(delta, base::TimeDelta());
if (delta > GetMaxInterbufferDistance()) {
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_track_buffer_gap_warning_logs_,
kMaxTrackBufferGapWarningLogs)
<< "Media append that overlapped current playback position caused time "
"gap in playing "
<< GetStreamTypeName() << " stream because the next keyframe is "
<< delta.InMilliseconds() << "ms beyond last overlapped frame. Media "
"may appear temporarily frozen.";
}
}
DecodeTimestamp SourceBufferStream::GetNextBufferTimestamp() {
if (!track_buffer_.empty())
return track_buffer_.front()->GetDecodeTimestamp();
if (!selected_range_) return kNoDecodeTimestamp();
DCHECK(selected_range_->HasNextBufferPosition());
return selected_range_->GetNextTimestamp();
}
SourceBufferStream::RangeList::iterator
SourceBufferStream::FindExistingRangeFor(DecodeTimestamp start_timestamp) {
for (RangeList::iterator itr = ranges_.begin(); itr != ranges_.end(); ++itr) {
if ((*itr)->BelongsToRange(start_timestamp)) return itr;
}
return ranges_.end();
}
SourceBufferStream::RangeList::iterator SourceBufferStream::AddToRanges(
SourceBufferRange* new_range) {
DecodeTimestamp start_timestamp = new_range->GetStartTimestamp();
RangeList::iterator itr = ranges_.end();
for (itr = ranges_.begin(); itr != ranges_.end(); ++itr) {
if ((*itr)->GetStartTimestamp() > start_timestamp) break;
}
return ranges_.insert(itr, new_range);
}
SourceBufferStream::RangeList::iterator
SourceBufferStream::GetSelectedRangeItr() {
DCHECK(selected_range_);
RangeList::iterator itr = ranges_.end();
for (itr = ranges_.begin(); itr != ranges_.end(); ++itr) {
if (*itr == selected_range_) break;
}
DCHECK(itr != ranges_.end());
return itr;
}
void SourceBufferStream::SeekAndSetSelectedRange(
SourceBufferRange* range, DecodeTimestamp seek_timestamp) {
if (range) range->Seek(seek_timestamp);
SetSelectedRange(range);
}
void SourceBufferStream::SetSelectedRange(SourceBufferRange* range) {
DVLOG(1) << __func__ << " " << GetStreamTypeName() << ": " << selected_range_
<< " " << (selected_range_ ? RangeToString(*selected_range_) : "")
<< " -> " << range << " " << (range ? RangeToString(*range) : "");
if (selected_range_) selected_range_->ResetNextBufferPosition();
DCHECK(!range || range->HasNextBufferPosition());
selected_range_ = range;
}
Ranges<base::TimeDelta> SourceBufferStream::GetBufferedTime() const {
Ranges<base::TimeDelta> ranges;
for (RangeList::const_iterator itr = ranges_.begin(); itr != ranges_.end();
++itr) {
ranges.Add((*itr)->GetStartTimestamp().ToPresentationTime(),
(*itr)->GetBufferedEndTimestamp().ToPresentationTime());
}
return ranges;
}
base::TimeDelta SourceBufferStream::GetHighestPresentationTimestamp() const {
if (ranges_.empty()) return base::TimeDelta();
// TODO(wolenetz): Report actual highest PTS here, not DTS cast to PTS. See
// https://crbug.com/398130.
return ranges_.back()->GetEndTimestamp().ToPresentationTime();
}
base::TimeDelta SourceBufferStream::GetBufferedDuration() const {
if (ranges_.empty()) return base::TimeDelta();
return ranges_.back()->GetBufferedEndTimestamp().ToPresentationTime();
}
size_t SourceBufferStream::GetBufferedSize() const {
size_t ranges_size = 0;
for (RangeList::const_iterator iter = ranges_.begin(); iter != ranges_.end();
++iter)
ranges_size += (*iter)->size_in_bytes();
return ranges_size;
}
void SourceBufferStream::MarkEndOfStream() {
DCHECK(!end_of_stream_);
end_of_stream_ = true;
}
void SourceBufferStream::UnmarkEndOfStream() {
DCHECK(end_of_stream_);
end_of_stream_ = false;
}
bool SourceBufferStream::IsEndOfStreamReached() const {
if (!end_of_stream_ || !track_buffer_.empty()) return false;
if (ranges_.empty()) return true;
if (seek_pending_) {
base::TimeDelta last_range_end_time =
ranges_.back()->GetBufferedEndTimestamp().ToPresentationTime();
return seek_buffer_timestamp_ >= last_range_end_time;
}
if (!selected_range_) return true;
return selected_range_ == ranges_.back();
}
const AudioDecoderConfig& SourceBufferStream::GetCurrentAudioDecoderConfig() {
if (config_change_pending_) CompleteConfigChange();
return audio_configs_[current_config_index_];
}
const VideoDecoderConfig& SourceBufferStream::GetCurrentVideoDecoderConfig() {
if (config_change_pending_) CompleteConfigChange();
return video_configs_[current_config_index_];
}
const TextTrackConfig& SourceBufferStream::GetCurrentTextTrackConfig() {
return text_track_config_;
}
base::TimeDelta SourceBufferStream::GetMaxInterbufferDistance() const {
if (max_interbuffer_distance_ == kNoTimestamp)
return base::TimeDelta::FromMilliseconds(kDefaultBufferDurationInMs);
return max_interbuffer_distance_;
}
bool SourceBufferStream::UpdateAudioConfig(const AudioDecoderConfig& config) {
DCHECK(!audio_configs_.empty());
DCHECK(video_configs_.empty());
DVLOG(3) << "UpdateAudioConfig.";
if (audio_configs_[0].codec() != config.codec()) {
MEDIA_LOG(ERROR, media_log_) << "Audio codec changes not allowed.";
return false;
}
if (!audio_configs_[0].encryption_scheme().Matches(
config.encryption_scheme())) {
MEDIA_LOG(ERROR, media_log_) << "Audio encryption changes not allowed.";
return false;
}
// Check to see if the new config matches an existing one.
for (size_t i = 0; i < audio_configs_.size(); ++i) {
if (config.Matches(audio_configs_[i])) {
append_config_index_ = i;
return true;
}
}
// No matches found so let's add this one to the list.
append_config_index_ = audio_configs_.size();
DVLOG(2) << "New audio config - index: " << append_config_index_;
audio_configs_.resize(audio_configs_.size() + 1);
audio_configs_[append_config_index_] = config;
return true;
}
bool SourceBufferStream::UpdateVideoConfig(const VideoDecoderConfig& config) {
DCHECK(!video_configs_.empty());
DCHECK(audio_configs_.empty());
DVLOG(3) << "UpdateVideoConfig.";
if (video_configs_[0].codec() != config.codec()) {
MEDIA_LOG(ERROR, media_log_) << "Video codec changes not allowed.";
return false;
}
if (!video_configs_[0].encryption_scheme().Matches(
config.encryption_scheme())) {
MEDIA_LOG(ERROR, media_log_) << "Video encryption changes not allowed.";
return false;
}
// Check to see if the new config matches an existing one.
for (size_t i = 0; i < video_configs_.size(); ++i) {
if (config.Matches(video_configs_[i])) {
append_config_index_ = i;
return true;
}
}
// No matches found so let's add this one to the list.
append_config_index_ = video_configs_.size();
DVLOG(2) << "New video config - index: " << append_config_index_;
video_configs_.resize(video_configs_.size() + 1);
video_configs_[append_config_index_] = config;
VideoResolution resolution = GetVideoResolution(config.visible_rect().size());
// TODO: Reduce the memory limit when there is no more 4k samples cached.
if (resolution > kVideoResolution1080p) {
memory_limit_ = COBALT_MEDIA_BUFFER_VIDEO_BUDGET_4K;
}
return true;
}
void SourceBufferStream::CompleteConfigChange() {
config_change_pending_ = false;
if (pending_buffer_.get()) {
current_config_index_ =
pending_buffer_->GetSpliceBufferConfigId(splice_buffers_index_);
return;
}
if (!track_buffer_.empty()) {
current_config_index_ = track_buffer_.front()->GetSpliceBufferConfigId(0);
return;
}
if (selected_range_ && selected_range_->HasNextBuffer())
current_config_index_ = selected_range_->GetNextConfigId();
}
void SourceBufferStream::SetSelectedRangeIfNeeded(
const DecodeTimestamp timestamp) {
DVLOG(2) << __func__ << " " << GetStreamTypeName() << "("
<< timestamp.InSecondsF() << ")";
if (selected_range_) {
DCHECK(track_buffer_.empty());
return;
}
if (!track_buffer_.empty()) {
DCHECK(!selected_range_);
return;
}
DecodeTimestamp start_timestamp = timestamp;
// If the next buffer timestamp is not known then use a timestamp just after
// the timestamp on the last buffer returned by GetNextBuffer().
if (start_timestamp == kNoDecodeTimestamp()) {
if (last_output_buffer_timestamp_ == kNoDecodeTimestamp()) {
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< " no previous output timestamp";
return;
}
start_timestamp =
last_output_buffer_timestamp_ + base::TimeDelta::FromInternalValue(1);
}
DecodeTimestamp seek_timestamp =
FindNewSelectedRangeSeekTimestamp(start_timestamp);
// If we don't have buffered data to seek to, then return.
if (seek_timestamp == kNoDecodeTimestamp()) {
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< " couldn't find new selected range seek timestamp";
return;
}
DCHECK(track_buffer_.empty());
SeekAndSetSelectedRange(*FindExistingRangeFor(seek_timestamp),
seek_timestamp);
}
DecodeTimestamp SourceBufferStream::FindNewSelectedRangeSeekTimestamp(
const DecodeTimestamp start_timestamp) {
DCHECK(start_timestamp != kNoDecodeTimestamp());
DCHECK(start_timestamp >= DecodeTimestamp());
RangeList::iterator itr = ranges_.begin();
// When checking a range to see if it has or begins soon enough after
// |start_timestamp|, use the fudge room to determine "soon enough".
DecodeTimestamp start_timestamp_plus_fudge =
start_timestamp + ComputeFudgeRoom(GetMaxInterbufferDistance());
// Multiple ranges could be within the fudge room, because the fudge room is
// dynamic based on max inter-buffer distance seen so far. Optimistically
// check the earliest ones first.
for (; itr != ranges_.end(); ++itr) {
DecodeTimestamp range_start = (*itr)->GetStartTimestamp();
if (range_start >= start_timestamp_plus_fudge) break;
if ((*itr)->GetEndTimestamp() < start_timestamp) continue;
DecodeTimestamp search_timestamp = start_timestamp;
if (start_timestamp < range_start &&
start_timestamp_plus_fudge >= range_start) {
search_timestamp = range_start;
}
DecodeTimestamp keyframe_timestamp =
(*itr)->NextKeyframeTimestamp(search_timestamp);
if (keyframe_timestamp != kNoDecodeTimestamp()) return keyframe_timestamp;
}
DVLOG(2) << __func__ << " " << GetStreamTypeName()
<< " no buffered data for dts=" << start_timestamp.InSecondsF();
return kNoDecodeTimestamp();
}
DecodeTimestamp SourceBufferStream::FindKeyframeAfterTimestamp(
const DecodeTimestamp timestamp) {
DCHECK(timestamp != kNoDecodeTimestamp());
RangeList::iterator itr = FindExistingRangeFor(timestamp);
if (itr == ranges_.end()) return kNoDecodeTimestamp();
// First check for a keyframe timestamp >= |timestamp|
// in the current range.
return (*itr)->NextKeyframeTimestamp(timestamp);
}
std::string SourceBufferStream::GetStreamTypeName() const {
switch (GetType()) {
case kAudio:
return "AUDIO";
case kVideo:
return "VIDEO";
case kText:
return "TEXT";
}
NOTREACHED();
return "";
}
SourceBufferStream::Type SourceBufferStream::GetType() const {
if (!audio_configs_.empty()) return kAudio;
if (!video_configs_.empty()) return kVideo;
DCHECK_NE(text_track_config_.kind(), kTextNone);
return kText;
}
void SourceBufferStream::DeleteAndRemoveRange(RangeList::iterator* itr) {
DVLOG(1) << __func__;
DCHECK(*itr != ranges_.end());
if (**itr == selected_range_) {
DVLOG(1) << __func__ << " deleting selected range.";
SetSelectedRange(NULL);
}
if (*itr == range_for_next_append_) {
DVLOG(1) << __func__ << " deleting range_for_next_append_.";
range_for_next_append_ = ranges_.end();
ResetLastAppendedState();
}
delete **itr;
*itr = ranges_.erase(*itr);
}
void SourceBufferStream::GenerateSpliceFrame(const BufferQueue& new_buffers) {
DCHECK(!new_buffers.empty());
// Splice frames are only supported for audio.
if (GetType() != kAudio) return;
// Find the overlapped range (if any).
const base::TimeDelta splice_timestamp = new_buffers.front()->timestamp();
const DecodeTimestamp splice_dts =
DecodeTimestamp::FromPresentationTime(splice_timestamp);
RangeList::iterator range_itr = FindExistingRangeFor(splice_dts);
if (range_itr == ranges_.end()) return;
const DecodeTimestamp max_splice_end_dts =
splice_dts +
base::TimeDelta::FromMilliseconds(kCrossfadeDurationInMilliseconds);
// Find all buffers involved before the splice point.
BufferQueue pre_splice_buffers;
if (!(*range_itr)
->GetBuffersInRange(splice_dts, max_splice_end_dts,
&pre_splice_buffers)) {
return;
}
// If there are gaps in the timeline, it's possible that we only find buffers
// after the splice point but within the splice range. For simplicity, we do
// not generate splice frames in this case.
//
// We also do not want to generate splices if the first new buffer replaces an
// existing buffer exactly.
if (pre_splice_buffers.front()->timestamp() >= splice_timestamp) {
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_splice_generation_warning_logs_,
kMaxSpliceGenerationWarningLogs)
<< "Skipping splice frame generation: first new buffer at "
<< splice_timestamp.InMicroseconds()
<< "us begins at or before existing buffer at "
<< pre_splice_buffers.front()->timestamp().InMicroseconds() << "us.";
DVLOG(1) << "Skipping splice: overlapped buffers begin at or after the "
"first new buffer.";
return;
}
// If any |pre_splice_buffers| are already splices or preroll, do not generate
// a splice.
for (size_t i = 0; i < pre_splice_buffers.size(); ++i) {
const BufferQueue& original_splice_buffers =
pre_splice_buffers[i]->splice_buffers();
if (!original_splice_buffers.empty()) {
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_splice_generation_warning_logs_,
kMaxSpliceGenerationWarningLogs)
<< "Skipping splice frame generation: overlapped buffers at "
<< pre_splice_buffers[i]->timestamp().InMicroseconds()
<< "us are in a previously buffered splice.";
DVLOG(1) << "Can't generate splice: overlapped buffers contain a "
"pre-existing splice.";
return;
}
if (pre_splice_buffers[i]->preroll_buffer().get()) {
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_splice_generation_warning_logs_,
kMaxSpliceGenerationWarningLogs)
<< "Skipping splice frame generation: overlapped buffers at "
<< pre_splice_buffers[i]->timestamp().InMicroseconds()
<< "us contain preroll.";
DVLOG(1) << "Can't generate splice: overlapped buffers contain preroll.";
return;
}
}
// Don't generate splice frames which represent less than a millisecond (which
// is frequently the extent of timestamp resolution for poorly encoded media)
// or less than two samples (need at least two to crossfade).
const base::TimeDelta splice_duration =
pre_splice_buffers.back()->timestamp() +
pre_splice_buffers.back()->duration() - splice_timestamp;
const base::TimeDelta minimum_splice_duration = std::max(
base::TimeDelta::FromMilliseconds(1),
base::TimeDelta::FromSecondsD(
2.0 / audio_configs_[append_config_index_].samples_per_second()));
if (splice_duration < minimum_splice_duration) {
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_splice_generation_warning_logs_,
kMaxSpliceGenerationWarningLogs)
<< "Skipping splice frame generation: not enough samples for splicing "
"new buffer at "
<< splice_timestamp.InMicroseconds() << "us. Have "
<< splice_duration.InMicroseconds() << "us, but need "
<< minimum_splice_duration.InMicroseconds() << "us.";
DVLOG(1) << "Can't generate splice: not enough samples for crossfade; have "
<< splice_duration.InMicroseconds() << "us, but need "
<< minimum_splice_duration.InMicroseconds() << "us.";
return;
}
DVLOG(1) << "Generating splice frame @ " << new_buffers.front()->timestamp()
<< ", splice duration: " << splice_duration.InMicroseconds()
<< " us";
LIMITED_MEDIA_LOG(DEBUG, media_log_, num_splice_generation_success_logs_,
kMaxSpliceGenerationSuccessLogs)
<< "Generated splice of overlap duration "
<< splice_duration.InMicroseconds() << "us into new buffer at "
<< splice_timestamp.InMicroseconds() << "us.";
new_buffers.front()->ConvertToSpliceBuffer(pre_splice_buffers);
}
bool SourceBufferStream::SetPendingBuffer(
scoped_refptr<StreamParserBuffer>* out_buffer) {
DCHECK(out_buffer->get());
DCHECK(!pending_buffer_.get());
const bool have_splice_buffers = !(*out_buffer)->splice_buffers().empty();
const bool have_preroll_buffer = !!(*out_buffer)->preroll_buffer().get();
if (!have_splice_buffers && !have_preroll_buffer) return false;
DCHECK_NE(have_splice_buffers, have_preroll_buffer);
splice_buffers_index_ = 0;
pending_buffer_.swap(*out_buffer);
pending_buffers_complete_ = false;
return true;
}
base::TimeDelta SourceBufferStream::GetBufferedDurationForGarbageCollection()
const {
base::TimeDelta duration;
for (auto range : ranges_) {
duration += range->GetEndTimestamp() - range->GetStartTimestamp();
}
return duration;
}
} // namespace media
} // namespace cobalt