Module: libav Branch: release/0.8 Commit: feed0c6b6ae31cb3d5af144c74dd2040051780b7
Author: Dale Curtis <[email protected]> Committer: Alex Converse <[email protected]> Date: Fri Feb 24 13:17:39 2012 -0500 mpegaudiodec: Prevent premature clipping of mp3 input buffer. Instead of clipping extrasize based on EXTRABYTES, clip based on the amount of buffer actually left. Without this fix, there are warbles and other distortions in the test case below. http://kevincennis.com/mix/assets/sounds/1901_voxfx.mp3 (cherry picked from commit b7165426917f91ebcad84bdff366824f03b32bfe) Signed-off-by: Alex Converse <[email protected]> --- libavcodec/mpegaudiodec.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/libavcodec/mpegaudiodec.c b/libavcodec/mpegaudiodec.c index 04c1d98..d902573 100644 --- a/libavcodec/mpegaudiodec.c +++ b/libavcodec/mpegaudiodec.c @@ -40,6 +40,7 @@ #define BACKSTEP_SIZE 512 #define EXTRABYTES 24 +#define LAST_BUF_SIZE 2 * BACKSTEP_SIZE + EXTRABYTES /* layer 3 "granule" */ typedef struct GranuleDef { @@ -63,7 +64,7 @@ typedef struct GranuleDef { typedef struct MPADecodeContext { MPA_DECODE_HEADER - uint8_t last_buf[2 * BACKSTEP_SIZE + EXTRABYTES]; + uint8_t last_buf[LAST_BUF_SIZE]; int last_buf_size; /* next header (used in free format parsing) */ uint32_t free_format_next_header; @@ -1378,7 +1379,8 @@ static int mp_decode_layer3(MPADecodeContext *s) if (!s->adu_mode) { int skip; const uint8_t *ptr = s->gb.buffer + (get_bits_count(&s->gb)>>3); - int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0, EXTRABYTES); + int extrasize = av_clip(get_bits_left(&s->gb) >> 3, 0, + FFMAX(0, LAST_BUF_SIZE - s->last_buf_size)); assert((get_bits_count(&s->gb) & 7) == 0); /* now we get bits from the main_data_begin offset */ av_dlog(s->avctx, "seekback: %d\n", main_data_begin); _______________________________________________ libav-commits mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-commits
