From e5838c90ee522062c1780ea722f1d54ba5775575 Mon Sep 17 00:00:00 2001 From: Matthieu Castet Date: Sun, 11 May 2008 18:13:30 +0000 Subject: simplify decoding of uncompressed samples. patch by matthieu castet . Originally committed as revision 13120 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/alac.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-) (limited to 'libavcodec/alac.c') diff --git a/libavcodec/alac.c b/libavcodec/alac.c index 23037a5d6f..3ea7952ba0 100644 --- a/libavcodec/alac.c +++ b/libavcodec/alac.c @@ -115,6 +115,10 @@ static int alac_set_info(ALACContext *alac) alac->setinfo_max_samples_per_frame = bytestream_get_be32(&ptr); ptr++; /* ??? */ alac->setinfo_sample_size = *ptr++; + if (alac->setinfo_sample_size > 32) { + av_log(alac->avctx, AV_LOG_ERROR, "setinfo_sample_size too large\n"); + return -1; + } alac->setinfo_rice_historymult = *ptr++; alac->setinfo_rice_initialhistory = *ptr++; alac->setinfo_rice_kmodifier = *ptr++; @@ -531,33 +535,16 @@ static int alac_decode_frame(AVCodecContext *avctx, } } else { /* not compressed, easy case */ - if (alac->setinfo_sample_size <= 16) { - int i, chan; - for (chan = 0; chan < channels; chan++) - for (i = 0; i < outputsamples; i++) { - int32_t audiobits; - - audiobits = get_bits(&alac->gb, alac->setinfo_sample_size); - audiobits = extend_sign32(audiobits, readsamplesize); - - alac->outputsamples_buffer[chan][i] = audiobits; - } - } else { int i, chan; for (chan = 0; chan < channels; chan++) for (i = 0; i < outputsamples; i++) { int32_t audiobits; - audiobits = get_bits(&alac->gb, 16); - /* special case of sign extension.. - * as we'll be ORing the low 16bits into this */ - audiobits = audiobits << 16; - audiobits = audiobits >> (32 - alac->setinfo_sample_size); - audiobits |= get_bits(&alac->gb, alac->setinfo_sample_size - 16); + audiobits = get_bits_long(&alac->gb, alac->setinfo_sample_size); + audiobits = extend_sign32(audiobits, alac->setinfo_sample_size); alac->outputsamples_buffer[chan][i] = audiobits; } - } /* wasted_bytes = 0; */ interlacing_shift = 0; interlacing_leftweight = 0; -- cgit v1.2.3