[FFmpeg-devel] [PATCH]lavc/mjpegdec: Support 2:3 subsampling

Carl Eugen Hoyos ceffmpeg at gmail.com
Thu Oct 18 01:33:39 EEST 2018


2018-10-17 22:12 GMT+02:00, Michael Niedermayer <michael at niedermayer.cc>:
> On Wed, Oct 17, 2018 at 09:01:30PM +0200, Carl Eugen Hoyos wrote:
>> 2018-10-17 17:51 GMT+02:00, Michael Niedermayer <michael at niedermayer.cc>:
>> > On Wed, Oct 17, 2018 at 12:22:51AM +0200, Carl Eugen Hoyos wrote:
>> >> Hi!
>> >>
>> >> Attached patch allows decoding the sample from ticket #7495.
>> >>
>> >> Please review, Carl Eugen
>> >
>> >>  mjpegdec.c |   17 ++++++++++++++---
>> >>  1 file changed, 14 insertions(+), 3 deletions(-)
>> >> 8f0d03a533b42c35f2bd8d5bdae4dabd24b18f4c
>> >> 0001-lavc-mjpegdec-Support-2-3-subsampling.patch
>> >> From 0e9d2ec4e0cba36ba03a6b7470a707c0a3f88b8c Mon Sep 17 00:00:00 2001
>> >> From: Carl Eugen Hoyos <ceffmpeg at gmail.com>
>> >> Date: Wed, 17 Oct 2018 00:21:26 +0200
>> >> Subject: [PATCH] lavc/mjpegdec: Support 2:3 subsampling.
>> >>
>> >> Fixes ticket #7495.
>> >> ---
>> >>  libavcodec/mjpegdec.c |   17 ++++++++++++++---
>> >>  1 file changed, 14 insertions(+), 3 deletions(-)
>> >
>> > breaks
>> > make -j12 fate-tdsc
>>
>> New patch attached, please review.
>>
>> Thank you, Carl Eugen
>
>>  mjpegdec.c |   11 ++++++++---
>>  1 file changed, 8 insertions(+), 3 deletions(-)
>> 45ffa2918d1236d99637c96f84803a646e757cab
>> 0001-lavc-mjpegdec-Support-2-3-subsampling.patch
>> From 2a8917ad5f82184c10e41be776bf3d138b676a85 Mon Sep 17 00:00:00 2001
>> From: Carl Eugen Hoyos <ceffmpeg at gmail.com>
>> Date: Wed, 17 Oct 2018 21:00:37 +0200
>> Subject: [PATCH] lavc/mjpegdec: Support 2:3 subsampling.
>>
>> Fixes ticket #7495.
>> ---
>>  libavcodec/mjpegdec.c |   11 ++++++++---
>>  1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
>> index 35ee10d..cfc5de8 100644
>> --- a/libavcodec/mjpegdec.c
>> +++ b/libavcodec/mjpegdec.c
>> @@ -594,6 +594,7 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
>>          s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG :
>> AVCOL_RANGE_JPEG;
>>          break;
>>      case 0x22111100:
>> +    case 0x23111100:
>>      case 0x42111100:
>>      case 0x24111100:
>>          if (s->bits <= 8) s->avctx->pix_fmt = s->cs_itu601 ?
>> AV_PIX_FMT_YUV420P : AV_PIX_FMT_YUVJ420P;
>> @@ -607,6 +608,10 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
>>              if (s->bits > 8)
>>                  goto unk_pixfmt;
>>              s->upscale_v[1] = s->upscale_v[2] = 1;
>> +        } else if (pix_fmt_id == 0x23111100) {
>> +            if (s->bits > 8)
>> +                goto unk_pixfmt;
>> +            s->upscale_v[1] = s->upscale_v[2] = 2;
>>          }
>>          break;
>>      case 0x41111100:
>
> there remains code which does:
>             if (s->upscale_v[p])
>                 h = (h+1)>>1;
>
> didnt deeply check but doesnt this need an update or a assert upscale_v == 1
> ?

I updated the condition.

> no more comments from me about this patch

Patch applied.

Thank you, Carl Eugen


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