From 33f64fd5d588a82b8bae1b1b5ea627c0c80b01d6 Mon Sep 17 00:00:00 2001 From: Kostya Shishkov Date: Fri, 31 May 2013 21:09:27 +0200 Subject: [PATCH] indeo4: expand allowed quantiser range Indeo 4 has quantiser range 0-31 instead of 0-23 for Indeo 5, and clipping quantiser leads to incorrect quantisation and DC prediction on low-quality videos. This fixes bug 259. --- libavcodec/ivi_common.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libavcodec/ivi_common.c b/libavcodec/ivi_common.c index f11b729..f7e241b 100644 --- a/libavcodec/ivi_common.c +++ b/libavcodec/ivi_common.c @@ -418,7 +418,11 @@ static int ivi_decode_blocks(GetBitContext *gb, IVIBandDesc *band, IVITile *tile cbp = mb->cbp; buf_offs = mb->buf_offs; - quant = av_clip(band->glob_quant + mb->q_delta, 0, 23); + quant = band->glob_quant + mb->q_delta; + if (avctx->codec_id == AV_CODEC_ID_INDEO4) + quant = av_clip(quant, 0, 31); + else + quant = av_clip(quant, 0, 23); base_tab = is_intra ? band->intra_base : band->inter_base; scale_tab = is_intra ? band->intra_scale : band->inter_scale; -- 2.7.4