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
Does
for (i = 0; i < 3; i++)
for (j = 0; j < 2; j++)
av_reduce(&sc->mastering->display_primaries[i][j].num,
&sc->mastering->display_primaries[i][j].den,
lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den),
chroma_den, chroma_den);
for (i = 0; i < 2; i++)
av_reduce(&sc->mastering->white_point[i].num,
&sc->mastering->white_point[i].den,
lrint(((double)avio_rb16(pb) / (1 << 16)) * chroma_den),
chroma_den, chroma_den);
av_reduce(&sc->mastering->max_luminance.num,
&sc->mastering->max_luminance.den,
lrint(((double)avio_rb32(pb) / (1 << 8)) * luma_den),
luma_den, INT_MAX);
av_reduce(&sc->mastering->min_luminance.num,
&sc->mastering->min_luminance.den,
lrint(((double)avio_rb32(pb) / (1 << 14)) * luma_den),
luma_den, INT_MAX);
Look better?
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