Support HLS MPEG2 TS with SAMPLE-AES encryption.

media/formats/mp2t/mp2t_stream_parser.h

 // Copyright 2014 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.
 
 #ifndef MEDIA_FORMATS_MP2T_MP2T_STREAM_PARSER_H_
 #define MEDIA_FORMATS_MP2T_MP2T_STREAM_PARSER_H_
 
 #include <stdint.h>
 
 #include <list>
 #include <map>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/byte_queue.h"
+#include "media/base/decrypt_config.h"
 #include "media/base/media_export.h"
 #include "media/base/stream_parser.h"
 #include "media/base/video_decoder_config.h"
 #include "media/formats/mp2t/timestamp_unroller.h"
+#include "media/media_features.h"
 
 namespace media {
 
+class DecryptConfig;
 class StreamParserBuffer;
 
 namespace mp2t {
 
+class Descriptors;
 class PidState;
 
 class MEDIA_EXPORT Mp2tStreamParser : public StreamParser {
  public:
   explicit Mp2tStreamParser(bool sbr_in_mimetype);
   ~Mp2tStreamParser() override;
 
   // StreamParser implementation.
   void Init(const InitCB& init_cb,
             const NewConfigCB& config_cb,
             const NewBuffersCB& new_buffers_cb,
             bool ignore_text_tracks,
             const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
             const NewMediaSegmentCB& new_segment_cb,
             const EndMediaSegmentCB& end_of_segment_cb,
             const scoped_refptr<MediaLog>& media_log) override;
   void Flush() override;
   bool Parse(const uint8_t* buf, int size) override;
 
  private:
-  typedef std::map<int, PidState*> PidMap;
+  using PidMap = std::map<int, PidState*>;
+  using PidMapElement = std::pair<int, PidState*>;
 
   struct BufferQueueWithConfig {
     BufferQueueWithConfig(bool is_cfg_sent,
                           const AudioDecoderConfig& audio_cfg,
                           const VideoDecoderConfig& video_cfg);
     ~BufferQueueWithConfig();
 
     bool is_config_sent;
     AudioDecoderConfig audio_config;
     StreamParser::BufferQueue audio_queue;
     VideoDecoderConfig video_config;
     StreamParser::BufferQueue video_queue;
   };
 
   // Callback invoked to register a Program Map Table.
   // Note: Does nothing if the PID is already registered.
   void RegisterPmt(int program_number, int pmt_pid);
 
   // Callback invoked to register a PES pid.
   // Possible values for |stream_type| are defined in:
   // ISO-13818.1 / ITU H.222 Table 2.34 "Stream type assignments".
   // |pes_pid| is part of the Program Map Table refered by |pmt_pid|.
-  void RegisterPes(int pmt_pid, int pes_pid, int stream_type);
+  // Some stream types are qualified by additional |descriptors|.
+  void RegisterPes(int pmt_pid,
+                   int pes_pid,
+                   int stream_type,
+                   const Descriptors& descriptors);
 
   // Since the StreamParser interface allows only one audio & video streams,
   // an automatic PID filtering should be applied to select the audio & video
   // streams.
   void UpdatePidFilter();
 
   // Callback invoked each time the audio/video decoder configuration is
   // changed.
   void OnVideoConfigChanged(int pes_pid,
                             const VideoDecoderConfig& video_decoder_config);
   void OnAudioConfigChanged(int pes_pid,
                             const AudioDecoderConfig& audio_decoder_config);
 
   // Invoke the initialization callback if needed.
   bool FinishInitializationIfNeeded();
 
   // Callback invoked by the ES stream parser
   // to emit a new audio/video access unit.
   void OnEmitAudioBuffer(
       int pes_pid,
       scoped_refptr<StreamParserBuffer> stream_parser_buffer);
   void OnEmitVideoBuffer(
       int pes_pid,
       scoped_refptr<StreamParserBuffer> stream_parser_buffer);
   bool EmitRemainingBuffers();
 
+#if BUILDFLAG(ENABLE_HLS_SAMPLE_AES)

[ddorwin, 2016/04/12 00:40:48]

Is this the best object for storing some of these things, especially the
DecryptConfig? Would it make any sense to put them in a separate object to
minimize the number of #ifdefs and intermingling/interdependence with the common
code?

[dougsteed, 2016/05/08 23:18:44]

I've explored this a little, and it could be done. My approach would be to
define a Mpt2StreamParserCenc class that has the definitions and state
associated with Part 9. An Mp2tStreamParser instance would contain a
Mps2tStreamParserCenc instance if necessary. However, because of the way that
the CENC PIDs and TsSections need to be defined, this approach would require
some of the implementation details of Mp2tStreamParser (including StreamType and
PidState) to be factored out so they are available to both classes. Not sure if
that is a net gain worthwhile. 

+  // Register the parser for CA Table.

[ddorwin, 2016/04/12 00:40:47]

s/Register/Set/?

[dougsteed, 2016/05/08 23:18:44]

Was using the existing terminology q.v. RegisterPmt() and RegisterPes()

+  PidMap::iterator RegisterCat();
+  void UnregisterCat();
+
+  // Register the PIDs for the Cenc packets (CENC-ECM and CENC-PSSH).
+  void RegisterCencPids(int ca_pid, int pssh_pid);
+  void UnregisterCencPids();
+
+  // Register the DecryptConfig (parsed from CENC-ECM).
+  void RegisterDecryptConfig(const DecryptConfig& config);
+
+  // Register the PSSH (parsed from CENC-PSSH).
+  void RegisterPsshBoxes(const std::vector<uint8_t>& init_data);
+
+  const DecryptConfig* GetDecryptConfig() { return decrypt_config_.get(); }

[ddorwin, 2016/04/12 00:40:48]

See below regarding "external" or other naming. This might apply to multiple of
these.

+#endif
+
   // List of callbacks.
   InitCB init_cb_;
   NewConfigCB config_cb_;
   NewBuffersCB new_buffers_cb_;
   EncryptedMediaInitDataCB encrypted_media_init_data_cb_;
   NewMediaSegmentCB new_segment_cb_;
   EndMediaSegmentCB end_of_segment_cb_;
   scoped_refptr<MediaLog> media_log_;
 
   // True when AAC SBR extension is signalled in the mimetype
@@ skipping 17 matching lines @@
   bool is_initialized_;
 
   // Indicate whether a segment was started.
   bool segment_started_;
 
   // Timestamp unroller.
   // Timestamps in PES packets must be unrolled using the same offset.
   // So the unroller is global between PES pids.
   TimestampUnroller timestamp_unroller_;
 
+#if BUILDFLAG(ENABLE_HLS_SAMPLE_AES)
+  scoped_ptr<DecryptConfig> decrypt_config_;

[ddorwin, 2016/04/12 00:40:48]

Why does only Sample AES need a config? Perhaps this is an "external" config or
something like that. If so, it might be helpful to specify this in the name.

[dougsteed, 2016/05/08 23:18:44]

It's not really "external", it is derived from information conveyed in an
CENC-ECM packet. Eventually this will be needed when Part 9 is fully
implemented. For now it is only needed for Sample AES. I thought about changing
the name to GetCurrentDecryptoConfig or GetCencDecryptConfig, but concluded that
I like the current name better.

+#endif
+
   DISALLOW_COPY_AND_ASSIGN(Mp2tStreamParser);
 };
 
 }  // namespace mp2t
 }  // namespace media
 
 #endif