Hi,
the attached patch fixes part of ticket #3874, for the part ffmpeg's
encoder is responsible for. The remainder of the issue is decoders not
correctly handling unusual chroma subsamplings.
Note: I have kept the computation from the width in raw bytes as I
suspect this can be the worst case for lzw code expansion.
--
Christophe
From 9ec9a913fbfc6238de915c360df2324c309636fb Mon Sep 17 00:00:00 2001
From: Christophe Gisquet <christophe.gisq...@gmail.com>
Date: Sun, 12 Oct 2014 21:10:54 +0200
Subject: [PATCH] tiffenc: properly compute packet size
The bytes per row is a better indication of it.
Helps resolving ticket #3874 by fixing ffmpeg's encoder and transforming
the issue in a issue with non-compliant decoders. ffmpeg's one is ok,
but unfortunately, many aren't handling correctling unusual chroma
samplings.
---
libavcodec/tiffenc.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/libavcodec/tiffenc.c b/libavcodec/tiffenc.c
index 5a61f1a..138d214 100644
--- a/libavcodec/tiffenc.c
+++ b/libavcodec/tiffenc.c
@@ -305,7 +305,9 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
strips = (s->height - 1) / s->rps + 1;
- packet_size = avctx->height * ((avctx->width * s->bpp + 7) >> 3) * 2 +
+ bytes_per_row = (((s->width - 1) / s->subsampling[0] + 1) * s->bpp *
+ s->subsampling[0] * s->subsampling[1] + 7) >> 3;
+ packet_size = avctx->height * bytes_per_row * 2 +
avctx->height * 4 + FF_MIN_BUFFER_SIZE;
if ((ret = ff_alloc_packet2(avctx, pkt, packet_size)) < 0)
@@ -333,8 +335,6 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
goto fail;
}
- bytes_per_row = (((s->width - 1) / s->subsampling[0] + 1) * s->bpp *
- s->subsampling[0] * s->subsampling[1] + 7) >> 3;
if (is_yuv) {
av_fast_padded_malloc(&s->yuv_line, &s->yuv_line_size, bytes_per_row);
if (s->yuv_line == NULL) {
--
1.9.2.msysgit.0
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