1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef MEDIA_FILTERS_AUDIO_FILE_READER_H_ 6 #define MEDIA_FILTERS_AUDIO_FILE_READER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/memory/scoped_ptr.h" 10 #include "media/base/media_export.h" 11 #include "media/filters/ffmpeg_glue.h" 12 13 struct AVCodecContext; 14 struct AVPacket; 15 struct AVStream; 16 17 namespace base { class TimeDelta; } 18 19 namespace media { 20 21 class AudioBus; 22 class FFmpegURLProtocol; 23 24 class MEDIA_EXPORT AudioFileReader { 25 public: 26 // Audio file data will be read using the given protocol. 27 // The AudioFileReader does not take ownership of |protocol| and 28 // simply maintains a weak reference to it. 29 explicit AudioFileReader(FFmpegURLProtocol* protocol); 30 virtual ~AudioFileReader(); 31 32 // Open() reads the audio data format so that the sample_rate(), 33 // channels(), GetDuration(), and GetNumberOfFrames() methods can be called. 34 // It returns |true| on success. 35 bool Open(); 36 void Close(); 37 38 // After a call to Open(), attempts to fully fill |audio_bus| with decoded 39 // audio data. Any unfilled frames will be zeroed out. 40 // |audio_data| must be of the same size as channels(). 41 // The audio data will be decoded as floating-point linear PCM with 42 // a nominal range of -1.0 -> +1.0. 43 // Returns the number of sample-frames actually read which will always be 44 // <= audio_bus->frames() 45 int Read(AudioBus* audio_bus); 46 47 // These methods can be called once Open() has been called. 48 int channels() const { return channels_; } 49 int sample_rate() const { return sample_rate_; } 50 51 // Please note that GetDuration() and GetNumberOfFrames() attempt to be 52 // accurate, but are only estimates. For some encoded formats, the actual 53 // duration of the file can only be determined once all the file data has been 54 // read. The Read() method returns the actual number of sample-frames it has 55 // read. 56 base::TimeDelta GetDuration() const; 57 int GetNumberOfFrames() const; 58 59 // The methods below are helper methods which allow AudioFileReader to double 60 // as a test utility for demuxing audio files. 61 // -------------------------------------------------------------------------- 62 63 // Similar to Open() but does not initialize the decoder. 64 bool OpenDemuxerForTesting(); 65 66 // Returns true if a packet could be demuxed from the first audio stream in 67 // the file, |output_packet| will contain the demuxed packet then. 68 bool ReadPacketForTesting(AVPacket* output_packet); 69 70 // Seeks to the given point and returns true if successful. |seek_time| will 71 // be converted to the stream's time base automatically. 72 bool SeekForTesting(base::TimeDelta seek_time); 73 74 const AVStream* GetAVStreamForTesting() const; 75 const AVCodecContext* codec_context_for_testing() const { 76 return codec_context_; 77 } 78 79 private: 80 bool OpenDemuxer(); 81 bool OpenDecoder(); 82 bool ReadPacket(AVPacket* output_packet); 83 84 scoped_ptr<FFmpegGlue> glue_; 85 AVCodecContext* codec_context_; 86 int stream_index_; 87 FFmpegURLProtocol* protocol_; 88 int channels_; 89 int sample_rate_; 90 int64_t end_padding_; 91 92 // AVSampleFormat initially requested; not Chrome's SampleFormat. 93 int av_sample_format_; 94 95 DISALLOW_COPY_AND_ASSIGN(AudioFileReader); 96 }; 97 98 } // namespace media 99 100 #endif // MEDIA_FILTERS_AUDIO_FILE_READER_H_ 101
