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.
This commit is contained in:
Alex Converse 2011-04-26 14:29:03 -04:00 committed by Justin Ruggles
parent f4e043ff63
commit e4744b59aa

View File

@ -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++) {