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
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel