From dcaa83a0fccb3bd63eb71c48d70c1adfc97e4102 Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Wed, 5 Oct 2011 20:07:29 -0400 Subject: [PATCH] alacdec: read/validate number of channels from the extradata. check frame header channel count against header/container channel count. --- libavcodec/alac.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/libavcodec/alac.c b/libavcodec/alac.c index 5e376ac..d4926e8 100644 --- a/libavcodec/alac.c +++ b/libavcodec/alac.c @@ -119,7 +119,7 @@ static int alac_set_info(ALACContext *alac) alac->setinfo_rice_historymult = *ptr++; alac->setinfo_rice_initialhistory = *ptr++; alac->setinfo_rice_kmodifier = *ptr++; - ptr++; /* channels? */ + alac->numchannels = *ptr++; bytestream_get_be16(&ptr); /* ??? */ bytestream_get_be32(&ptr); /* max coded frame size */ bytestream_get_be32(&ptr); /* bitrate ? */ @@ -456,10 +456,9 @@ static int alac_decode_frame(AVCodecContext *avctx, init_get_bits(&alac->gb, inbuffer, input_buffer_size * 8); channels = get_bits(&alac->gb, 3) + 1; - if (channels > MAX_CHANNELS) { - av_log(avctx, AV_LOG_ERROR, "channels > %d not supported\n", - MAX_CHANNELS); - return -1; + if (channels != avctx->channels) { + av_log(avctx, AV_LOG_ERROR, "frame header channel count mismatch\n"); + return AVERROR_INVALIDDATA; } /* 2^result = something to do with output waiting. @@ -634,7 +633,6 @@ static av_cold int alac_decode_init(AVCodecContext * avctx) { ALACContext *alac = avctx->priv_data; alac->avctx = avctx; - alac->numchannels = alac->avctx->channels; /* initialize from the extradata */ if (alac->avctx->extradata_size != ALAC_EXTRADATA_SIZE) { @@ -657,6 +655,21 @@ static av_cold int alac_decode_init(AVCodecContext * avctx) return -1; } + if (alac->numchannels < 1) { + av_log(avctx, AV_LOG_WARNING, "Invalid channel count\n"); + alac->numchannels = avctx->channels; + } else { + if (alac->numchannels > MAX_CHANNELS) + alac->numchannels = avctx->channels; + else + avctx->channels = alac->numchannels; + } + if (avctx->channels > MAX_CHANNELS) { + av_log(avctx, AV_LOG_ERROR, "Unsupported channel count: %d\n", + avctx->channels); + return AVERROR_PATCHWELCOME; + } + return 0; } -- 2.7.4