DTS: implement support for core-less XLL extension substreams

ChangeLog

@@ -1,5 +1,8 @@
 2015-03-28  Moritz Bunkus  <moritz@bunkus.org>
 
+        * mkvmerge: enhancement: Implemented support for core-less DTS
+        streams consisting solely of XLL extension sub-streams.
+
         * mkvmerge: new feature: track selection can be done by language
         codes as well. Affects the options --audio-tracks,
         --button-tracks, --subtitle-tracks and --video-tracks. Works only

src/common/dts.cpp

@@ -48,6 +48,13 @@ static const channel_arrangement channel_arrangements[16] = {
   // other modes are not defined as of yet
 };
 
+static unsigned int const s_substream_sample_rates[16] = {
+    8000,  16000,  32000,  64000,
+  128000,  22050,  44100,  88200,
+  176400, 352800,  12000,  24000,
+   48000,  96000, 192000, 384000
+};
+
 static const int core_samplefreqs[16] = {
      -1, 8000, 16000, 32000,    -1,    -1, 11025, 22050,
   44100,   -1,    -1, 12000, 24000, 48000,    -1,    -1
@@ -552,16 +559,50 @@ header_t::decode_lbr_header(bit_reader_c &bc,
   return true;
 }
 
+bool
+header_t::decode_xll_header(bit_reader_c &bc,
+                            substream_asset_t &asset) {
+  bc.set_bit_position(asset.xll_offset * 8);
+  if (bc.get_bits(32) != static_cast<uint32_t>(sync_word_e::xll))
+    return false;
+
+  if (!has_core && !(asset.extension_mask & exss_lbr))
+    core_sampling_frequency = substream_assets[0].max_sample_rate;
+
+  return true;
+
+  // // Decode common header.
+  // bc.skip_bits(4);              // version
+  // auto header_size     = bc.get_bits(8);
+  // auto frame_size_bits = bc.get_bits(5);
+  // bc.skip_bits(frame_size_bits); // frame size
+
+  // auto num_channel_sets = bc.get_bits(4);
+  // if (!num_channel_sets)
+  //   return false;
+
+  // bc.skip_bits(4);              // num segments in frame
+  // auto num_samples_in_segment = 1 << bc.get_bits(4);
+
+  // bc.set_bit_position(asset.xll_offset * 8 + header_size);
+
+  // // Decode first channel set sub-header.
+  // bc.skip_bits(10);             // channel set header size
+  // auto channel_set_ll_channel = bc.get_bits(4);
+  // bc.skip_bits(channel_set_ll_channel); // residual channel encode
+  // bc.skip_bits(5 + 5);                  // bit resolution, bit width
+
+  // auto sampling_frequency_idx      = bc.get_bits(4);
+  // auto sampling_frequency_modifier = bc.get_bits(2);
+  // if (!has_core && !(asset.extension_mask & exss_lbr))
+  //   core_sampling_frequency = substream_assets[0].max_sample_rate;
+
+  // return true;
+}
+
 bool
 header_t::decode_asset(bit_reader_c &bc,
                        substream_asset_t &asset) {
-  static unsigned int const s_substream_sample_rates[16] = {
-      8000,  16000,  32000,  64000,
-    128000,  22050,  44100,  88200,
-    176400, 352800,  12000,  24000,
-     48000,  96000, 192000, 384000
-  };
-
   auto descriptor_pos  = bc.get_bit_position();
   auto descriptor_size = bc.get_bits(9) + 1;
   asset.asset_index    = bc.get_bits(3);
@@ -708,6 +749,9 @@ header_t::decode_asset(bit_reader_c &bc,
   if ((asset.extension_mask & exss_lbr) && !decode_lbr_header(bc, asset))
     return false;
 
+  if ((asset.extension_mask & exss_xll) && !decode_xll_header(bc, asset))
+    return false;
+
   if (asset.extension_mask & exss_xll)
     dts_type = dts_type_e::master_audio;
 

src/common/dts.h

@@ -26,6 +26,7 @@ enum class sync_word_e {
     core = 0x7ffe8001
   , exss = 0x64582025
   , lbr  = 0x0a801921
+  , xll  = 0x41a29547
 };
 
 enum class frametype_e {
@@ -236,6 +237,7 @@ public:
 protected:
   bool decode_asset(bit_reader_c &bc, substream_asset_t &asset);
   bool decode_lbr_header(bit_reader_c &bc, substream_asset_t &asset);
+  bool decode_xll_header(bit_reader_c &bc, substream_asset_t &asset);
   void parse_lbr_parameters(bit_reader_c &bc, substream_asset_t &asset);
   void parse_xll_parameters(bit_reader_c &bc, substream_asset_t &asset);
 

tests/results.txt

@@ -329,3 +329,4 @@ T_480dts_express:564af1cf4765e27e054d248ccb214cd6-f4a3abe81bdf0fb40a6ba8c0983e3e
 T_481dts_hd_high_resolution:18be2234293a4ca12ecfa0c1648e853e-edb2e77c3a778f2fd0b3fe5db71637c1:passed:20150326-184450:1.647462876
 T_482hevc_no_aspect_ratio_in_sps:6ee3a0bc21ccabde46a8c7af049b120e-3d1417ef349f58a50c768a13b6daf2d4-3f56f42c30cdffd70c4992a1eaeb2332:passed:20150327-125855:0.880932303
 T_483select_tracks_by_language:29372d441ceb28c4619b67bb4341ad31+3c1bb1b57f532c27a6e4ee3f5d9490f2+3c1bb1b57f532c27a6e4ee3f5d9490f2+3c1bb1b57f532c27a6e4ee3f5d9490f2+8addc95582a81fae7df19cf954945fe3:passed:20150328-191349:0.156972906
+T_484dts_without_core_xll_substream:f562501d11cc5c773bae34670b50d7b4:passed:20150328-221149:0.468020256

tests/test-484dts_without_core_xll_substream.rb

@@ -0,0 +1,5 @@
+#!/usr/bin/ruby -w
+
+# T_484dts_without_core_xll_substream
+describe "mkvmerge / DTS file without cores, only XLL extension substreams"
+test_merge "data/dts/xll-no-core.dts"