1 // Copyright 2013 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_BASE_AUDIO_BUFFER_H_ 6 #define MEDIA_BASE_AUDIO_BUFFER_H_ 7 8 #include <vector> 9 10 #include "base/memory/aligned_memory.h" 11 #include "base/memory/ref_counted.h" 12 #include "base/memory/scoped_ptr.h" 13 #include "base/time/time.h" 14 #include "media/base/media_export.h" 15 #include "media/base/sample_format.h" 16 17 namespace media { 18 class AudioBus; 19 20 // An audio buffer that takes a copy of the data passed to it, holds it, and 21 // copies it into an AudioBus when needed. Also supports an end of stream 22 // marker. 23 class MEDIA_EXPORT AudioBuffer 24 : public base::RefCountedThreadSafe<AudioBuffer> { 25 public: 26 // Create an AudioBuffer whose channel data is copied from |data|. For 27 // interleaved data, only the first buffer is used. For planar data, the 28 // number of buffers must be equal to |channel_count|. |frame_count| is the 29 // number of frames in each buffer. |data| must not be null and |frame_count| 30 // must be >= 0. 31 // 32 // TODO(jrummell): Compute duration rather than pass it in. 33 static scoped_refptr<AudioBuffer> CopyFrom(SampleFormat sample_format, 34 int channel_count, 35 int frame_count, 36 const uint8* const* data, 37 const base::TimeDelta timestamp, 38 const base::TimeDelta duration); 39 40 // Create an AudioBuffer with |frame_count| frames. Buffer is allocated, but 41 // not initialized. Timestamp and duration are set to kNoTimestamp(). 42 static scoped_refptr<AudioBuffer> CreateBuffer(SampleFormat sample_format, 43 int channel_count, 44 int frame_count); 45 46 // Create an empty AudioBuffer with |frame_count| frames. 47 static scoped_refptr<AudioBuffer> CreateEmptyBuffer( 48 int channel_count, 49 int frame_count, 50 const base::TimeDelta timestamp, 51 const base::TimeDelta duration); 52 53 // Create a AudioBuffer indicating we've reached end of stream. 54 // Calling any method other than end_of_stream() on the resulting buffer 55 // is disallowed. 56 static scoped_refptr<AudioBuffer> CreateEOSBuffer(); 57 58 // Copy frames into |dest|. |frames_to_copy| is the number of frames to copy. 59 // |source_frame_offset| specifies how many frames in the buffer to skip 60 // first. |dest_frame_offset| is the frame offset in |dest|. The frames are 61 // converted from their source format into planar float32 data (which is all 62 // that AudioBus handles). 63 void ReadFrames(int frames_to_copy, 64 int source_frame_offset, 65 int dest_frame_offset, 66 AudioBus* dest); 67 68 // Trim an AudioBuffer by removing |frames_to_trim| frames from the start. 69 // Timestamp and duration are adjusted to reflect the fewer frames. 70 // Note that repeated calls to TrimStart() may result in timestamp() and 71 // duration() being off by a few microseconds due to rounding issues. 72 void TrimStart(int frames_to_trim); 73 74 // Trim an AudioBuffer by removing |frames_to_trim| frames from the end. 75 // Duration is adjusted to reflect the fewer frames. 76 void TrimEnd(int frames_to_trim); 77 78 // Return the number of channels. 79 int channel_count() const { return channel_count_; } 80 81 // Return the number of frames held. 82 int frame_count() const { return adjusted_frame_count_; } 83 84 // Access to constructor parameters. 85 base::TimeDelta timestamp() const { return timestamp_; } 86 base::TimeDelta duration() const { return duration_; } 87 88 // TODO(jrummell): Remove set_timestamp() and set_duration() once 89 // DecryptingAudioDecoder::EnqueueFrames() is changed to set them when 90 // creating the buffer. See http://crbug.com/255261. 91 void set_timestamp(base::TimeDelta timestamp) { timestamp_ = timestamp; } 92 void set_duration(base::TimeDelta duration) { duration_ = duration; } 93 94 // If there's no data in this buffer, it represents end of stream. 95 bool end_of_stream() const { return end_of_stream_; } 96 97 // Access to the raw buffer for ffmpeg to write directly to. Data for planar 98 // data is grouped by channel. 99 uint8* writable_data() { return data_.get(); } 100 101 private: 102 friend class base::RefCountedThreadSafe<AudioBuffer>; 103 104 // Allocates aligned contiguous buffer to hold all channel data (1 block for 105 // interleaved data, |channel_count| blocks for planar data), copies 106 // [data,data+data_size) to the allocated buffer(s). If |data| is null, no 107 // data is copied. If |create_buffer| is false, no data buffer is created (or 108 // copied to). 109 AudioBuffer(SampleFormat sample_format, 110 int channel_count, 111 int frame_count, 112 bool create_buffer, 113 const uint8* const* data, 114 const base::TimeDelta timestamp, 115 const base::TimeDelta duration); 116 117 virtual ~AudioBuffer(); 118 119 const SampleFormat sample_format_; 120 const int channel_count_; 121 int adjusted_frame_count_; 122 int trim_start_; 123 const bool end_of_stream_; 124 base::TimeDelta timestamp_; 125 base::TimeDelta duration_; 126 127 // Contiguous block of channel data. 128 scoped_ptr_malloc<uint8, base::ScopedPtrAlignedFree> data_; 129 130 // For planar data, points to each channels data. 131 std::vector<uint8*> channel_data_; 132 133 DISALLOW_IMPLICIT_CONSTRUCTORS(AudioBuffer); 134 }; 135 136 } // namespace media 137 138 #endif // MEDIA_BASE_AUDIO_BUFFER_H_ 139
