On 5/26/2017 8:55 PM, James Almer wrote: > On 5/26/2017 8:05 PM, Michael Niedermayer wrote: >> On Wed, May 17, 2017 at 09:49:40PM -0300, James Almer wrote: >>> As defined in "VP Codec ISO Media File Format Binding v1.0" >>> https://github.com/webmproject/vp9-dash/blob/master/VPCodecISOMediaFileFormatBinding.md >>> >>> Partially based on Matroska decoder code. >>> >>> Signed-off-by: James Almer <jamr...@gmail.com> >>> --- >>> libavformat/isom.h | 2 ++ >>> libavformat/mov.c | 65 >>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>> 2 files changed, 67 insertions(+) >>> >>> diff --git a/libavformat/isom.h b/libavformat/isom.h >>> index d9956cf63a..426f732247 100644 >>> --- a/libavformat/isom.h >>> +++ b/libavformat/isom.h >>> @@ -27,6 +27,7 @@ >>> #include <stddef.h> >>> #include <stdint.h> >>> >>> +#include "libavutil/mastering_display_metadata.h" >>> #include "libavutil/spherical.h" >>> #include "libavutil/stereo3d.h" >>> >>> @@ -194,6 +195,7 @@ typedef struct MOVStreamContext { >>> AVStereo3D *stereo3d; >>> AVSphericalMapping *spherical; >>> size_t spherical_size; >>> + AVMasteringDisplayMetadata *mastering; >>> >>> uint32_t format; >>> >>> diff --git a/libavformat/mov.c b/libavformat/mov.c >>> index afef53b79a..0b5fd849f3 100644 >>> --- a/libavformat/mov.c >>> +++ b/libavformat/mov.c >>> @@ -4612,6 +4612,60 @@ static int mov_read_tmcd(MOVContext *c, AVIOContext >>> *pb, MOVAtom atom) >>> return 0; >>> } >>> >>> +static int mov_read_smdm(MOVContext *c, AVIOContext *pb, MOVAtom atom) >>> +{ >>> + MOVStreamContext *sc; >>> + const int chroma_den = 50000; >>> + const int luma_den = 10000; >>> + int version; >>> + >>> + if (c->fc->nb_streams < 1) >>> + return AVERROR_INVALIDDATA; >>> + >>> + sc = c->fc->streams[c->fc->nb_streams - 1]->priv_data; >>> + >>> + if (atom.size < 5) { >>> + av_log(c->fc, AV_LOG_ERROR, "Empty Mastering Display Metadata >>> box\n"); >>> + return AVERROR_INVALIDDATA; >>> + } >>> + >>> + version = avio_r8(pb); >>> + if (version) { >>> + av_log(c->fc, AV_LOG_WARNING, "Unsupported Mastering Display >>> Metadata box version %d\n", version); >>> + return 0; >>> + } >>> + avio_skip(pb, 3); /* flags */ >>> + >>> + sc->mastering = av_mastering_display_metadata_alloc(); >>> + if (!sc->mastering) >>> + return AVERROR(ENOMEM); >>> + >> >>> + sc->mastering->display_primaries[0][0] = >>> + av_make_q(lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den), >>> chroma_den); >> >> this is not optimal, precission wise >> av_d2q() should produce closer rationals >> alternativly av_reduce() can be used directly >> >> but iam not sure why a fixed chroma_den and luma_den is fixed >> maybe iam missing something > > I took the constants from hevcdec.c and matroskadec.c and basically > copied how they handled these values. > At least based on what lavf's dump.c and mkvtoolnix's mkvinfo reported, > this implementation is the most precise i tried. Using av_d2q() directly > was worse.
By dump.c i mean i remuxed an mkv file with mastering metadata using the muxer implementation of this same patchset then compared the reported values. By mkvinfo i mean mkv -> mov (using my muxer implementation) -> mkv roundtrip then compared the double precision values stored in the original mkv and the new mkv. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
