[FFmpeg-devel] [PATCH 1/2 v2] fftools/ffmpeg: support applying container level cropping

[Anton Khirnov]

Quoting James Almer (2024-05-31 01:22:51)
> @@ -1000,11 +1001,21 @@ int ist_filter_add(InputStream *ist, InputFilter *ifilter, int is_simple,
>      ist->filters[ist->nb_filters - 1] = ifilter;
>  
>      if (ist->par->codec_type == AVMEDIA_TYPE_VIDEO) {
> +        const AVPacketSideData *sd = av_packet_side_data_get(ist->par->coded_side_data,
> +                                                             ist->par->nb_coded_side_data,
> +                                                             AV_PKT_DATA_FRAME_CROPPING);
>          if (ist->framerate.num > 0 && ist->framerate.den > 0) {
>              opts->framerate = ist->framerate;
>              opts->flags |= IFILTER_FLAG_CFR;
>          } else
>              opts->framerate = av_guess_frame_rate(d->f.ctx, ist->st, NULL);
> +        if (sd && sd->size == sizeof(uint32_t) * 4) {
> +            opts->crop_top    = AV_RL32(sd->data +  0);
> +            opts->crop_bottom = AV_RL32(sd->data +  4);
> +            opts->crop_left   = AV_RL32(sd->data +  8);
> +            opts->crop_right  = AV_RL32(sd->data + 12);
> +            opts->flags      |= IFILTER_FLAG_CROP;
> +        }
>      } else if (ist->par->codec_type == AVMEDIA_TYPE_SUBTITLE) {
>          /* Compute the size of the canvas for the subtitles stream.
>             If the subtitles codecpar has set a size, use it. Otherwise use the
> @@ -1241,6 +1252,9 @@ static int ist_add(const OptionsContext *o, Demuxer *d, AVStream *st)
>      ds->autorotate = 1;
>      MATCH_PER_STREAM_OPT(autorotate, i, ds->autorotate, ic, st);
>  
> +    ds->apply_cropping = 1;
> +    MATCH_PER_STREAM_OPT(apply_cropping, i, ds->apply_cropping, ic, st);
> +
>      MATCH_PER_STREAM_OPT(codec_tags, str, codec_tag, ic, st);
>      if (codec_tag) {
>          uint32_t tag = strtol(codec_tag, &next, 0);
> @@ -1362,6 +1376,8 @@ static int ist_add(const OptionsContext *o, Demuxer *d, AVStream *st)
>  
>      ds->dec_opts.flags |= DECODER_FLAG_BITEXACT * !!o->bitexact;
>  
> +    av_dict_set_int(&ds->decoder_opts, "apply_cropping", ds->apply_cropping, 0);

If I'm reading it right, this new option now applies only to decoder
cropping (breaking syntax, because AVOptions always take an argument),
while container cropping is always applied unconditionally.

That seems wrong.

-- 
Anton Khirnov