Add support for parsing VPx track codec private data.

Currently only the VP9 profile level is supported.

http://www.webmproject.org/vp9/profiles/

Change-Id: Iff7238e104621b53fdd51a67d752bd72b2dbbacb

common/hdr_util.cc

@@ -111,4 +111,72 @@ bool CopyColour(const mkvparser::Colour& parser_colour,
   }
   return true;
 }
+
+// Format of VPx private data:
+//
+//   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//  |    ID Byte    |             Length            |               |
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+               |
+//  |                                                               |
+//  :               Bytes 1..Length of Codec Feature                :
+//  |                                                               |
+//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+//
+// ID Byte Format
+// ID byte is an unsigned byte.
+//   0 1 2 3 4 5 6 7
+//  +-+-+-+-+-+-+-+-+
+//  |X|    ID       |
+//  +-+-+-+-+-+-+-+-+
+//
+// The X bit is reserved.
+//
+// Currently only profile level is supported. ID byte must be set to 1, and
+// length must be 1. Supported values are:
+//
+//   10: Level 1
+//   11: Level 1.1
+//   20: Level 2
+//   21: Level 2.1
+//   30: Level 3
+//   31: Level 3.1
+//   40: Level 4
+//   41: Level 4.1
+//   50: Level 5
+//   51: Level 5.1
+//   52: Level 5.2
+//   60: Level 6
+//   61: Level 6.1
+//   62: Level 6.2
+//
+// See the following link for more information:
+// http://www.webmproject.org/vp9/profiles/
+int ParseVpxCodecPrivate(const uint8_t* private_data, int32_t length) {
+  const int kVpxCodecPrivateLength = 3;
+  if (!private_data || length != kVpxCodecPrivateLength)
+    return 0;
+
+  const uint8_t id_byte = *private_data;
+  if (id_byte != 1)
+    return 0;
+
+  const int kVpxProfileLength = 1;
+  const uint8_t length_byte = private_data[1];
+  if (length_byte != kVpxProfileLength)
+    return 0;
+
+  const int level = static_cast<int>(private_data[2]);
+
+  const int kNumLevels = 14;
+  const int levels[kNumLevels] = {10, 11, 20, 21, 30, 31, 40,
+                                  41, 50, 51, 52, 60, 61, 62};
+
+  for (int i = 0; i < kNumLevels; ++i) {
+    if (level == levels[i])
+      return level;
+  }
+
+  return 0;
+}
 }  // namespace libwebm

common/hdr_util.h

@@ -8,6 +8,8 @@
 #ifndef LIBWEBM_COMMON_HDR_UTIL_H_
 #define LIBWEBM_COMMON_HDR_UTIL_H_
 
+#include <stdint.h>
+
 #include <memory>
 
 #include "mkvmuxer/mkvmuxer.h"
@@ -41,6 +43,9 @@ bool ColourValuePresent(long long value);
 bool CopyColour(const mkvparser::Colour& parser_colour,
                 mkvmuxer::Colour* muxer_colour);
 
+// Returns VP9 profile upon success or 0 upon failure.
+int ParseVpxCodecPrivate(const uint8_t* private_data, int32_t length);
+
 }  // namespace libwebm
 
 #endif  // LIBWEBM_COMMON_HDR_UTIL_H_

testing/parser_tests.cc

@@ -14,6 +14,7 @@
 #include <iomanip>
 #include <string>
 
+#include "common/hdr_util.h"
 #include "mkvparser/mkvparser.h"
 #include "mkvparser/mkvreader.h"
 #include "testing/test_util.h"
@@ -662,6 +663,27 @@ TEST_F(ParserTest, StereoModeParsedCorrectly) {
   EXPECT_EQ(144, video_track->GetDisplayHeight());
 }
 
+TEST_F(ParserTest, Vp9CodecProfileTest) {
+  const int kCodecPrivateLength = 3;
+
+  // Test invalid codec private data; all of these should return 0.
+  const uint8_t bad_codec_private[kCodecPrivateLength] = {0, 0, 0};
+  EXPECT_EQ(0, libwebm::ParseVpxCodecPrivate(NULL, kCodecPrivateLength));
+  EXPECT_EQ(0, libwebm::ParseVpxCodecPrivate(&bad_codec_private[0], 0));
+  EXPECT_EQ(0, libwebm::ParseVpxCodecPrivate(&bad_codec_private[0],
+                                             kCodecPrivateLength));
+  const uint8_t good_codec_private[kCodecPrivateLength] = {1, 1, 11};
+
+  // Test parse of codec private chunks, but lie about length.
+  EXPECT_EQ(0, libwebm::ParseVpxCodecPrivate(&bad_codec_private[0], 0));
+  EXPECT_EQ(0, libwebm::ParseVpxCodecPrivate(&good_codec_private[0], 0));
+
+  // Test a valid codec private; this should return 11.
+  // ID: 1, Length: 1, Profile: 11
+  EXPECT_EQ(11, libwebm::ParseVpxCodecPrivate(&good_codec_private[0],
+                                              kCodecPrivateLength));
+}
+
 }  // namespace test
 
 int main(int argc, char* argv[]) {

webm_info.cc

@@ -16,6 +16,7 @@
 #include <string>
 #include <vector>
 
+#include "common/hdr_util.h"
 #include "common/indent.h"
 #include "common/webm_constants.h"
 #include "common/webm_endian.h"
@@ -364,10 +365,22 @@ bool OutputTracks(const mkvparser::Segment& segment, const Options& options,
     size_t private_size;
     const unsigned char* const private_data =
         track->GetCodecPrivate(private_size);
-    if (private_data)
+    if (private_data) {
       fprintf(o, "%sPrivateData(size): %d\n", indent->indent_str().c_str(),
               static_cast<int>(private_size));
 
+      if (track_type == mkvparser::Track::kVideo) {
+        const std::string codec_id = track->GetCodecId();
+        const std::string v_vp9 = "V_VP9";
+        if (codec_id == v_vp9) {
+          const int vp9_profile_level =
+              libwebm::ParseVpxCodecPrivate(private_data, private_size);
+          fprintf(o, "%sVP9 profile level: %d\n", indent->indent_str().c_str(),
+                  vp9_profile_level);
+        }
+      }
+    }
+
     const uint64_t default_duration = track->GetDefaultDuration();
     if (default_duration > 0)
       fprintf(o, "%sDefaultDuration: %" PRIu64 "\n",