[FFmpeg-devel] [PATCH 1/2] hevcdec: Miss the location of chroma samples when exporting stream parameters

[Hendrik Leppkes]

On Wed, May 16, 2018 at 8:11 PM, wm4 <nfxjfg at googlemail.com> wrote:
> On Wed, 16 May 2018 15:19:44 +0800
> Haihao Xiang <haihao.xiang at intel.com> wrote:
>
>> Signed-off-by: Haihao Xiang <haihao.xiang at intel.com>
>> ---
>>  libavcodec/hevcdec.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
>> index c8877626d2..13d868bb4f 100644
>> --- a/libavcodec/hevcdec.c
>> +++ b/libavcodec/hevcdec.c
>> @@ -344,6 +344,11 @@ static void export_stream_params(AVCodecContext *avctx, const HEVCParamSets *ps,
>>          avctx->colorspace      = AVCOL_SPC_UNSPECIFIED;
>>      }
>>
>> +    if (sps->vui.chroma_loc_info_present_flag)
>> +        avctx->chroma_sample_location = sps->vui.chroma_sample_loc_type_top_field + 1;
>> +    else
>> +        avctx->chroma_sample_location = AVCHROMA_LOC_UNSPECIFIED;
>> +
>>      if (vps->vps_timing_info_present_flag) {
>>          num = vps->vps_num_units_in_tick;
>>          den = vps->vps_time_scale;
>
> Wouldn't this prevent an API user from setting the field to a container
> value as a fallback? Although maybe that's not necessary because
> there's an "unspecified" special value anyway.

The decoder always manages that value, if the SPS/PPS/VPS changed
mid-stream and the value vanishes, that also needs to be able to be
communicated.

- Hendrik