1 // Copyright (c) 2012 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_DEMUXER_STREAM_H_ 6 #define MEDIA_BASE_DEMUXER_STREAM_H_ 7 8 #include "base/callback.h" 9 #include "base/memory/ref_counted.h" 10 #include "media/base/media_export.h" 11 12 namespace media { 13 14 class AudioDecoderConfig; 15 class DecoderBuffer; 16 class VideoDecoderConfig; 17 18 class MEDIA_EXPORT DemuxerStream { 19 public: 20 enum Type { 21 UNKNOWN, 22 AUDIO, 23 VIDEO, 24 TEXT, 25 NUM_TYPES, // Always keep this entry as the last one! 26 }; 27 28 // Status returned in the Read() callback. 29 // kOk : Indicates the second parameter is Non-NULL and contains media data 30 // or the end of the stream. 31 // kAborted : Indicates an aborted Read(). This can happen if the 32 // DemuxerStream gets flushed and doesn't have any more data to 33 // return. The second parameter MUST be NULL when this status is 34 // returned. 35 // kConfigChange : Indicates that the AudioDecoderConfig or 36 // VideoDecoderConfig for the stream has changed. 37 // The DemuxerStream expects an audio_decoder_config() or 38 // video_decoder_config() call before Read() will start 39 // returning DecoderBuffers again. The decoder will need this 40 // new configuration to properly decode the buffers read 41 // from this point forward. The second parameter MUST be NULL 42 // when this status is returned. 43 // This will only be returned if SupportsConfigChanges() 44 // returns 'true' for this DemuxerStream. 45 enum Status { 46 kOk, 47 kAborted, 48 kConfigChanged, 49 }; 50 51 // Request a buffer to returned via the provided callback. 52 // 53 // The first parameter indicates the status of the read. 54 // The second parameter is non-NULL and contains media data 55 // or the end of the stream if the first parameter is kOk. NULL otherwise. 56 typedef base::Callback<void(Status, 57 const scoped_refptr<DecoderBuffer>&)>ReadCB; 58 virtual void Read(const ReadCB& read_cb) = 0; 59 60 // Returns the audio decoder configuration. It is an error to call this method 61 // if type() != AUDIO. 62 virtual AudioDecoderConfig audio_decoder_config() = 0; 63 64 // Returns the video decoder configuration. It is an error to call this method 65 // if type() != VIDEO. 66 virtual VideoDecoderConfig video_decoder_config() = 0; 67 68 // Returns the type of stream. 69 virtual Type type() = 0; 70 71 virtual void EnableBitstreamConverter() = 0; 72 73 // Whether or not this DemuxerStream allows midstream configuration changes. 74 // 75 // A DemuxerStream that returns 'true' to this may return the 'kConfigChange' 76 // status from a Read() call. In this case the client is expected to be 77 // capable of taking appropriate action to handle config changes. Otherwise 78 // audio_decoder_config() and video_decoder_config()'s return values are 79 // guaranteed to remain constant, and the client may make optimizations based 80 // on this. 81 virtual bool SupportsConfigChanges() = 0; 82 83 protected: 84 // Only allow concrete implementations to get deleted. 85 virtual ~DemuxerStream(); 86 }; 87 88 } // namespace media 89 90 #endif // MEDIA_BASE_DEMUXER_STREAM_H_ 91
