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| author | Alex Converse <alex.converse@gmail.com> | 2011-04-26 14:29:03 -0400 |
|---|---|---|
| committer | Justin Ruggles <justin.ruggles@gmail.com> | 2011-04-27 12:39:37 -0400 |
| commit | e4744b59aadd6e7064491c0228d6248289a6a85a (patch) | |
| tree | a230b3de82f8617a35a174cd14a0658f17cb7f62 | |
| parent | f4e043ff63935a71b98a36bc98b501c36ceadb92 (diff) | |
| download | ffmpeg-streaming-e4744b59aadd6e7064491c0228d6248289a6a85a.zip ffmpeg-streaming-e4744b59aadd6e7064491c0228d6248289a6a85a.tar.gz | |
Large intensity stereo and PNS indices are legal. Clip them instead of
erroring out. A magnitude of 100 corresponds to 2^25 so the will most
likely result in clipped output anyway.
None of the conformance streams fall in the range that need to be clipped.
| -rw-r--r-- | libavcodec/aacdec.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/libavcodec/aacdec.c b/libavcodec/aacdec.c index 0c6312f..e289caa 100644 --- a/libavcodec/aacdec.c +++ b/libavcodec/aacdec.c @@ -791,7 +791,8 @@ static int decode_scalefactors(AACContext *ac, float sf[120], GetBitContext *gb, { const int sf_offset = ac->sf_offset + (ics->window_sequence[0] == EIGHT_SHORT_SEQUENCE ? 12 : 0); int g, i, idx = 0; - int offset[3] = { global_gain, global_gain - 90, 100 }; + int offset[3] = { global_gain, global_gain - 90, 0 }; + int clipped_offset; int noise_flag = 1; static const char *sf_str[3] = { "Global gain", "Noise gain", "Intensity stereo position" }; for (g = 0; g < ics->num_window_groups; g++) { @@ -803,12 +804,14 @@ static int decode_scalefactors(AACContext *ac, float sf[120], GetBitContext *gb, } else if ((band_type[idx] == INTENSITY_BT) || (band_type[idx] == INTENSITY_BT2)) { for (; i < run_end; i++, idx++) { offset[2] += get_vlc2(gb, vlc_scalefactors.table, 7, 3) - 60; - if (offset[2] > 255U) { - av_log(ac->avctx, AV_LOG_ERROR, - "%s (%d) out of range.\n", sf_str[2], offset[2]); - return -1; + clipped_offset = av_clip(offset[2], -155, 100); + if (offset[2] != clipped_offset) { + av_log_ask_for_sample(ac->avctx, "Intensity stereo " + "position clipped (%d -> %d).\nIf you heard an " + "audible artifact, there may be a bug in the " + "decoder. ", offset[2], clipped_offset); } - sf[idx] = ff_aac_pow2sf_tab[-offset[2] + 300]; + sf[idx] = ff_aac_pow2sf_tab[-clipped_offset + 200]; } } else if (band_type[idx] == NOISE_BT) { for (; i < run_end; i++, idx++) { @@ -816,12 +819,14 @@ static int decode_scalefactors(AACContext *ac, float sf[120], GetBitContext *gb, offset[1] += get_bits(gb, 9) - 256; else offset[1] += get_vlc2(gb, vlc_scalefactors.table, 7, 3) - 60; - if (offset[1] > 255U) { - av_log(ac->avctx, AV_LOG_ERROR, - "%s (%d) out of range.\n", sf_str[1], offset[1]); - return -1; + clipped_offset = av_clip(offset[1], -100, 155); + if (offset[2] != clipped_offset) { + av_log_ask_for_sample(ac->avctx, "Noise gain clipped " + "(%d -> %d).\nIf you heard an audible " + "artifact, there may be a bug in the decoder. ", + offset[1], clipped_offset); } - sf[idx] = -ff_aac_pow2sf_tab[offset[1] + sf_offset + 100]; + sf[idx] = -ff_aac_pow2sf_tab[clipped_offset + sf_offset + 100]; } } else { for (; i < run_end; i++, idx++) { |
