[FFmpeg-devel] [PATCH] avcodec/mjpegdec: add support for decoding jpeg rgb file with subsampling

Wang Chuan ouchuanm at outlook.com
Sun Mar 26 05:13:43 EEST 2023


Fixes ticket #10190

Signed-off-by: Wang Chuan <ouchuanm at outlook.com>
---
  libavcodec/mjpegdec.c | 21 +++++++++++++++++++++
  1 file changed, 21 insertions(+)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index c833d66c4d..aa58f336d4 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -574,6 +574,27 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
              if (s->bits <= 8) s->avctx->pix_fmt = s->cs_itu601 ? 
AV_PIX_FMT_YUV444P : AV_PIX_FMT_YUVJ444P;
              else
                  goto unk_pixfmt;
+            if (s->component_id[0] == 'R' && s->component_id[1] == 'G' 
&& s->component_id[2] == 'B') {
+                if (s->bits <= 8)
+                    s->avctx->pix_fmt = AV_PIX_FMT_GBRP;
+                else
+                    goto unk_pixfmt;
+                if (pix_fmt_id == 0x22221100) {
+                    s->upscale_h[0] = s->upscale_v[0] = 0;
+                    s->upscale_h[1] = s->upscale_v[1] = 1;
+                    s->upscale_h[2] = s->upscale_v[2] = 0;
+                } else if (pix_fmt_id == 0x22112200) {
+                    s->upscale_h[0] = s->upscale_v[0] = 1;
+                    s->upscale_h[1] = s->upscale_v[1] = 0;
+                    s->upscale_h[2] = s->upscale_v[2] = 0;
+                } else if (pix_fmt_id == 0x11222200) {
+                    s->upscale_h[0] = s->upscale_v[0] = 0;
+                    s->upscale_h[1] = s->upscale_v[1] = 0;
+                    s->upscale_h[2] = s->upscale_v[2] = 1;
+                } else {
+                    goto unk_pixfmt;
+                }
+            }
              s->avctx->color_range = s->cs_itu601 ? AVCOL_RANGE_MPEG : 
AVCOL_RANGE_JPEG;
              break;
          case 0x11000000:
-- 
2.37.1 (Apple Git-137.1)



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