On Sat, Oct 29, 2011 at 10:49:15AM -0700, Luca Barbato wrote: > On 10/29/11 10:40 AM, Kostya Shishkov wrote: > >If the frame is filled with the same colour, encoder may produce no data > >and the fill value is indicated by zero code length (the rest of symbols > >will have 0xFF for code length, meaning invalid). So such Huffman trees > >should be treated specially. > > Seems ok
Sorry, built it on old master, here's on the current one (with my yesterday change).
>From c90727dfd6d0586a3854b81677bdee335004dc0d Mon Sep 17 00:00:00 2001 From: Kostya Shishkov <[email protected]> Date: Sat, 29 Oct 2011 19:35:20 +0200 Subject: [PATCH] utvideo: handle empty Huffman trees If the frame is filled with the same colour, encoder may produce no data and the fill value is indicated by zero code length (the rest of symbols will have 0xFF for code length, meaning invalid). So such Huffman trees should be treated specially. --- libavcodec/utvideo.c | 37 +++++++++++++++++++++++++++++++++---- 1 files changed, 33 insertions(+), 4 deletions(-) diff --git a/libavcodec/utvideo.c b/libavcodec/utvideo.c index 5faaa15..4c3b2a1 100644 --- a/libavcodec/utvideo.c +++ b/libavcodec/utvideo.c @@ -66,7 +66,7 @@ static int huff_cmp(const void *a, const void *b) return (aa->len - bb->len)*256 + aa->sym - bb->sym; } -static int build_huff(const uint8_t *src, VLC *vlc) +static int build_huff(const uint8_t *src, VLC *vlc, int *fsym) { int i; HuffEntry he[256]; @@ -76,13 +76,18 @@ static int build_huff(const uint8_t *src, VLC *vlc) uint8_t syms[256]; uint32_t code; + *fsym = -1; for (i = 0; i < 256; i++) { he[i].sym = i; he[i].len = *src++; } qsort(he, 256, sizeof(*he), huff_cmp); - if (!he[0].len || he[0].len > 32) + if (!he[0].len) { + *fsym = he[0].sym; + return 0; + } + if (he[0].len > 32) return -1; last = 255; @@ -112,13 +117,37 @@ static int decode_plane(UtvideoContext *c, int plane_no, int sstart, send; VLC vlc; GetBitContext gb; - int prev; + int prev, fsym; const int cmask = ~(!plane_no && c->avctx->pix_fmt == PIX_FMT_YUV420P); - if (build_huff(src, &vlc)) { + if (build_huff(src, &vlc, &fsym)) { av_log(c->avctx, AV_LOG_ERROR, "Cannot build Huffman codes\n"); return AVERROR_INVALIDDATA; } + if (fsym >= 0) { // build_huff reported a symbol to fill slices with + send = 0; + for (slice = 0; slice < c->slices; slice++) { + uint8_t *dest; + + sstart = send; + send = (height * (slice + 1) / c->slices) & cmask; + dest = dst + sstart * stride; + + prev = 0x80; + for (j = sstart; j < send; j++) { + for (i = 0; i < width * step; i += step) { + pix = fsym; + if (use_pred) { + prev += pix; + pix = prev; + } + dest[i] = pix; + } + dest += stride; + } + } + return 0; + } src += 256; src_size -= 256; -- 1.7.0.4
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