Hi!
Attached patch allows decoding the sample from ticket #7495.
Please review, Carl Eugen
From 0e9d2ec4e0cba36ba03a6b7470a707c0a3f88b8c Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffm...@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(-)
diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 35ee10d..0a81c0e 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:
@@ -2592,9 +2597,15 @@ the_end:
}
dst = &((uint8_t *)s->picture_ptr->data[p])[(h - 1) * s->linesize[p]];
for (i = h - 1; i; i--) {
- uint8_t *src1 = &((uint8_t *)s->picture_ptr->data[p])[i / 2 * s->linesize[p]];
- uint8_t *src2 = &((uint8_t *)s->picture_ptr->data[p])[(i + 1) / 2 * s->linesize[p]];
- if (src1 == src2 || i == h - 1) {
+ uint8_t *src1, *src2;
+ if (s->upscale_v[p] == 2) {
+ src1 = &((uint8_t *)s->picture_ptr->data[p])[i * 2 / 3 * s->linesize[p]];
+ src2 = &((uint8_t *)s->picture_ptr->data[p])[(i + 1) * 2 / 3 * s->linesize[p]];
+ } else {
+ src1 = &((uint8_t *)s->picture_ptr->data[p])[i / 2 * s->linesize[p]];
+ src2 = &((uint8_t *)s->picture_ptr->data[p])[(i + 1) / 2 * s->linesize[p]];
+ }
+ if (s->upscale_v[p] != 2 && (src1 == src2 || i == h - 1)) {
memcpy(dst, src1, w);
} else {
for (index = 0; index < w; index++)
--
1.7.10.4
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