blob: be5cdd0bc47a10f9f995f5cee0564bb76f64978d [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 <stdint.h>
#include "base/callback.h"
#include "base/macros.h"
#include "base/synchronization/lock.h"
#include "base/synchronization/waitable_event.h"
#include "media/filters/ffmpeg_glue.h"
namespace media {
class DataSource;
// An implementation of FFmpegURLProtocol that blocks until the underlying
// asynchronous DataSource::Read() operation completes. Generally constructed on
// the media thread and used by ffmpeg through the AVIO interface from a
// sequenced blocking pool.
class MEDIA_EXPORT BlockingUrlProtocol : public FFmpegURLProtocol {
// Implements FFmpegURLProtocol using the given |data_source|. |error_cb| is
// fired any time DataSource::Read() returns an error.
BlockingUrlProtocol(DataSource* data_source,
const base::RepeatingClosure& error_cb);
virtual ~BlockingUrlProtocol();
// Aborts any pending reads by returning a read error. After this method
// returns all subsequent calls to Read() will immediately fail. May be called
// from any thread and upon return ensures no further use of |data_source_|.
void Abort();
// FFmpegURLProtocol implementation.
int Read(int size, uint8_t* data) override;
bool GetPosition(int64_t* position_out) override;
bool SetPosition(int64_t position) override;
bool GetSize(int64_t* size_out) override;
bool IsStreaming() override;
// Sets |last_read_bytes_| and signals the blocked thread that the read
// has completed.
void SignalReadCompleted(int size);
// |data_source_lock_| allows Abort() to be called from any thread and stop
// all outstanding access to |data_source_|. Typically Abort() is called from
// the media thread while ffmpeg is operating on another thread.
base::Lock data_source_lock_;
DataSource* data_source_;
base::RepeatingClosure error_cb_;
const bool is_streaming_;
// Used to unblock the thread during shutdown and when reads complete.
base::WaitableEvent aborted_;
base::WaitableEvent read_complete_;
// Cached number of bytes last read from the data source.
int last_read_bytes_;
// Cached position within the data source.
int64_t read_position_;
} // namespace media