Detect VP9 in MP4

mp4/mp4ids.cpp

@@ -175,6 +175,7 @@ MediaFormat fourccToMediaFormat(std::uint32_t fourccId)
     case Vp8:
         return GeneralMediaFormat::Vp8;
     case Vp9:
+    case Vp9_2:
         return GeneralMediaFormat::Vp9;
     case WavPack:
         return MediaFormat(GeneralMediaFormat::WavPack);

mp4/mp4ids.h

@@ -386,6 +386,7 @@ enum KnownValue : std::uint32_t {
     Vdva = 0x76647661,
     Vp8 = 0x56503830, /**< VP8 video */
     Vp9 = 0x56503930, /**< VP9 video */
+    Vp9_2 = 0x76703039, /**< VP9 video */
     WavPack = 0x5756504B,
     WindowsMediaAudio = 0x6F776D61, /**< ? */
     WindowsMediaAudio7 = 0x574D4131,

mp4/mp4track.cpp

@@ -1706,6 +1706,7 @@ void Mp4Track::internalParseHeader(Diagnostics &diag)
                 case FourccIds::Hevc2:
                 case FourccIds::Av1_IVF:
                 case FourccIds::Av1_ISOBMFF:
+                case FourccIds::Vp9_2:
                     m_istream->seekg(6 + 2 + 16, ios_base::cur); // skip reserved bytes, data reference index, and reserved bytes (again)
                     m_pixelSize.setWidth(reader.readUInt16BE());
                     m_pixelSize.setHeight(reader.readUInt16BE());