Use header removal compression for MPEG-4 part 10 tracks with 4 bytes NALU size length

ChangeLog

@@ -1,5 +1,9 @@
 2010-07-12  Moritz Bunkus  <moritz@bunkus.org>
 
+	* mkvmerge: enhancement: Header removal compression has been
+	enabled by default for MPEG-4 part 10 (AVC/h.264) video tracks
+	with a NALU size field length of four bytes.
+
 	* mkvmerge: bug fix: Header removal compression has been
 	deactivated for MPEG-4 part 2 (aka DivX/Xvid) video tracks due to
 	incompatibility with packed bitstreams.

TODO

@@ -6,6 +6,4 @@ https://www.bunkus.org/bugzilla/buglist.cgi?query_format=advanced&product=mkvtoo
 
 Apart from that as a short reminder list for myself for the near future:
 
-- Enable header removal compression for MPEG-4 part 10 if the NALU size length is 4 (bug 519)
-
 - Write attachments before the clusters (bug 516)

src/common/compression.cpp

@@ -27,7 +27,7 @@
 using namespace libmatroska;
 
 const char *compression_methods[] = {
-  "unspecified", "zlib", "bz2", "lzo", "header_removal", "mpeg4_p2", "dirac", "dts", "ac3", "mp3", "analyze_header_removal", "none"
+  "unspecified", "zlib", "bz2", "lzo", "header_removal", "mpeg4_p2", "mpeg4_p10", "dirac", "dts", "ac3", "mp3", "analyze_header_removal", "none"
 };
 
 static const int compression_method_map[] = {
@@ -37,6 +37,7 @@ static const int compression_method_map[] = {
   2,                            // lzo1x
   3,                            // header removal
   3,                            // mpeg4_p2 is header removal
+  3,                            // mpeg4_p10 is header removal
   3,                            // dirac is header removal
   3,                            // dts is header removal
   3,                            // ac3 is header removal
@@ -373,6 +374,12 @@ mpeg4_p2_compressor_c::mpeg4_p2_compressor_c() {
   set_bytes(bytes);
 }
 
+mpeg4_p10_compressor_c::mpeg4_p10_compressor_c() {
+  memory_cptr bytes      = memory_c::alloc(1);
+  bytes->get_buffer()[0] = 0;
+  set_bytes(bytes);
+}
+
 dirac_compressor_c::dirac_compressor_c() {
   memory_cptr bytes = memory_c::alloc(4);
   put_uint32_be(bytes->get_buffer(), DIRAC_SYNC_WORD);
@@ -443,6 +450,9 @@ compressor_c::create(const char *method) {
   if (!strcasecmp(method, compression_methods[COMPRESSION_MPEG4_P2]))
     return compressor_ptr(new mpeg4_p2_compressor_c());
 
+  if (!strcasecmp(method, compression_methods[COMPRESSION_MPEG4_P10]))
+    return compressor_ptr(new mpeg4_p10_compressor_c());
+
   if (!strcasecmp(method, compression_methods[COMPRESSION_DIRAC]))
     return compressor_ptr(new dirac_compressor_c());
 

src/common/compression.h

@@ -32,6 +32,7 @@ enum compression_method_e {
   COMPRESSION_LZO,
   COMPRESSION_HEADER_REMOVAL,
   COMPRESSION_MPEG4_P2,
+  COMPRESSION_MPEG4_P10,
   COMPRESSION_DIRAC,
   COMPRESSION_DTS,
   COMPRESSION_AC3,
@@ -165,6 +166,11 @@ public:
   mpeg4_p2_compressor_c();
 };
 
+class MTX_DLL_API mpeg4_p10_compressor_c: public header_removal_compressor_c {
+public:
+  mpeg4_p10_compressor_c();
+};
+
 class MTX_DLL_API dirac_compressor_c: public header_removal_compressor_c {
 public:
   dirac_compressor_c();

src/common/mpeg4_p10.h

@@ -274,6 +274,10 @@ namespace mpeg4 {
         m_nalu_size_length = nalu_size_length;
       };
 
+      int get_nalu_size_length() {
+        return m_nalu_size_length;
+      };
+
       void ignore_nalu_size_length_errors() {
         m_ignore_nalu_size_length_errors = true;
       };

src/output/p_avc.cpp

@@ -61,6 +61,9 @@ mpeg4_p10_es_video_packetizer_c(generic_reader_c *p_reader,
   // duration/FPS itself.
   if (m_ti.m_ext_timecodes.empty())
     m_timecode_factory.clear();
+
+  if (4 == m_parser.get_nalu_size_length())
+    set_default_compression_method(COMPRESSION_MPEG4_P10);
 }
 
 void

src/output/p_mpeg4_p10.cpp

@@ -33,13 +33,15 @@ mpeg4_p10_video_packetizer_c(generic_reader_c *p_reader,
   , m_nalu_size_len_dst(0)
   , m_max_nalu_size(0)
 {
-
   m_relaxed_timecode_checking = true;
 
-  if ((NULL != m_ti.m_private_data) && (0 < m_ti.m_private_size)) {
-    setup_nalu_size_len_change();
+  setup_nalu_size_len_change();
+
+  if ((NULL != m_ti.m_private_data) && (0 < m_ti.m_private_size))
     set_codec_private(m_ti.m_private_data, m_ti.m_private_size);
-  }
+
+  if (4 == m_nalu_size_len_dst)
+    set_default_compression_method(COMPRESSION_MPEG4_P10);
 }
 
 void
@@ -78,7 +80,7 @@ mpeg4_p10_video_packetizer_c::process(packet_cptr packet) {
 
   m_ref_timecode = packet->timecode;
 
-  if (m_nalu_size_len_dst)
+  if (m_nalu_size_len_dst && (m_nalu_size_len_dst != m_nalu_size_len_src))
     change_nalu_size_len(packet);
 
   add_packet(packet);
@@ -111,6 +113,7 @@ mpeg4_p10_video_packetizer_c::setup_nalu_size_len_change() {
     return;
 
   m_nalu_size_len_src = (m_ti.m_private_data[4] & 0x03) + 1;
+  m_nalu_size_len_dst = m_nalu_size_len_src;
 
   if (!m_ti.m_nalu_size_length || (m_ti.m_nalu_size_length == m_nalu_size_len_src))
     return;