From 4285c2923cbc99256362c58d0d962aab03361334 Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Sun, 22 Mar 2009 19:12:02 +0000 Subject: [PATCH] flacdec: comments and white space. move skipping of frame header to decode_frame() Originally committed as revision 18150 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/flacdec.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/libavcodec/flacdec.c b/libavcodec/flacdec.c index 88f62f761a..93db63cd43 100644 --- a/libavcodec/flacdec.c +++ b/libavcodec/flacdec.c @@ -486,11 +486,15 @@ static int decode_frame(FLACContext *s, int alloc_data_size) int ch_mode, bps, blocksize, samplerate; GetBitContext *gb = &s->gb; - bs_code = get_bits(gb, 4); + /* frame sync code */ + skip_bits(&s->gb, 16); + /* block size and sample rate codes */ + bs_code = get_bits(gb, 4); sr_code = get_bits(gb, 4); - ch_mode = get_bits(gb, 4); /* channel assignment */ + /* channels and decorrelation */ + ch_mode = get_bits(gb, 4); if (ch_mode < FLAC_MAX_CHANNELS && s->channels == ch_mode+1) { ch_mode = FLAC_CHMODE_INDEPENDENT; } else if (ch_mode > FLAC_CHMODE_MID_SIDE || s->channels != 2) { @@ -499,6 +503,7 @@ static int decode_frame(FLACContext *s, int alloc_data_size) return -1; } + /* bits per sample */ bps_code = get_bits(gb, 3); if (bps_code == 0) bps= s->bps; @@ -520,16 +525,19 @@ static int decode_frame(FLACContext *s, int alloc_data_size) } s->bps = s->avctx->bits_per_raw_sample = bps; + /* reserved bit */ if (get_bits1(gb)) { av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n"); return -1; } + /* sample or frame count */ if (get_utf8(gb) < 0) { av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n"); return -1; } + /* blocksize */ if (bs_code == 0) { av_log(s->avctx, AV_LOG_ERROR, "reserved blocksize code: 0\n"); return -1; @@ -549,6 +557,7 @@ static int decode_frame(FLACContext *s, int alloc_data_size) if (blocksize * s->channels * (s->is32 ? 4 : 2) > alloc_data_size) return -1; + /* sample rate */ if (sr_code == 0) samplerate= s->samplerate; else if (sr_code < 12) @@ -565,6 +574,7 @@ static int decode_frame(FLACContext *s, int alloc_data_size) return -1; } + /* header CRC-8 check */ skip_bits(gb, 8); if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer, get_bits_count(gb)/8)) { @@ -665,7 +675,6 @@ static int flac_decode_frame(AVCodecContext *avctx, /* decode frame */ init_get_bits(&s->gb, buf, buf_size*8); - skip_bits(&s->gb, 16); if (decode_frame(s, alloc_data_size) < 0) { av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n"); s->bitstream_size=0;