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avcodec/aac/aacdec: support height channels signaled with PCE

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Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer
2026-06-02 20:06:00 -03:00
parent 070bd112be
commit a1e4aee2f0
2 changed files with 86 additions and 1 deletions
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libavcodec/aac/aacdec.c
+85
View File
@@ -875,6 +875,91 @@ static int decode_pce(AVCodecContext *avctx, MPEG4AudioConfig *m4ac,
av_log(avctx, AV_LOG_ERROR, "decode_pce: " overread_err);
return AVERROR_INVALIDDATA;
}
// Height extension
int height_ext = 0;
if (comment_len >= 16 + (num_front * 2 + num_side * 2 + num_back * 2))
height_ext = show_bits(gb, 8) == 0xAC;
if (height_ext) {
uint8_t height_map[4 /* ChannelPosition */][16 /* Channel */]; // 0 == base, 1 == top, 2 == bottom.
uint8_t tag[6 /* ChannelPosition */ ][16 /* Channel */][3];
int i, invalid = 0, height_tags = 0;
skip_bits(gb, 8);
// Read height extension bits to height_map, which define which layer each element belongs to.
// Also make a copy of layout_map that will then be used to rearrange it.
for (i = 0; i < num_front; i++) {
int height = get_bits(gb, 2);
invalid |= height > 2;
height_map [AAC_CHANNEL_FRONT][i] = height;
memcpy(&tag[AAC_CHANNEL_FRONT][i], layout_map + height_tags, sizeof(*layout_map));
height_tags++;
}
for (i = 0; i < num_side; i++) {
int height = get_bits(gb, 2);
invalid |= height > 2;
height_map [AAC_CHANNEL_SIDE][i] = height;
memcpy(&tag[AAC_CHANNEL_SIDE][i], layout_map + height_tags, sizeof(*layout_map));
height_tags++;
}
for (i = 0; i < num_back; i++) {
int height = get_bits(gb, 2);
invalid |= height > 2;
height_map [AAC_CHANNEL_BACK][i] = height;
memcpy(&tag[AAC_CHANNEL_BACK][i], layout_map + height_tags, sizeof(*layout_map));
height_tags++;
}
for (i = 0; i < num_lfe; i++) {
memcpy(&tag[AAC_CHANNEL_LFE][i], layout_map + height_tags, sizeof(*layout_map));
height_tags++;
}
for (i = 0; i < num_cc; i++) {
memcpy(&tag[AAC_CHANNEL_CC][i], layout_map + height_tags, sizeof(*layout_map));
height_tags++;
}
av_assert0(height_tags == tags);
if (!invalid) {
height_tags = 0;
// For each height layer, check that an element belongs to it and copy it back to layout_map.
// We need to take into account LFE and CC elements that may be present.
for (i = 0; i < 3; i++) {
for (int j = 0; j < num_front; j++) {
if (height_map[AAC_CHANNEL_FRONT][j] == i) {
memcpy(layout_map + height_tags, &tag[AAC_CHANNEL_FRONT][j], sizeof(*layout_map));
height_tags++;
}
}
for (int j = 0; j < num_side; j++) {
if (height_map[AAC_CHANNEL_SIDE][j] == i) {
memcpy(layout_map + height_tags, &tag[AAC_CHANNEL_SIDE][j], sizeof(*layout_map));
height_tags++;
}
}
for (int j = 0; j < num_back; j++) {
if (height_map[AAC_CHANNEL_BACK][j] == i) {
memcpy(layout_map + height_tags, &tag[AAC_CHANNEL_BACK][j], sizeof(*layout_map));
height_tags++;
}
}
if (i == 0) { // Base height, copy LFE and CC elements before moving to Top and Bottom
for (int j = 0; j < num_lfe; j++) {
memcpy(layout_map + height_tags, &tag[AAC_CHANNEL_LFE][j], sizeof(*layout_map));
height_tags++;
}
for (int j = 0; j < num_cc; j++, height_tags++) {
memcpy(layout_map + height_tags, &tag[AAC_CHANNEL_CC][j], sizeof(*layout_map));
height_tags++;
}
}
}
av_assert0(height_tags == tags);
}
comment_len -= 8 + (num_front * 2 + num_side * 2 + num_back * 2);
}
skip_bits_long(gb, comment_len);
return tags;
}
libavcodec/version.h
+1 -1
View File
@@ -30,7 +30,7 @@
#include "version_major.h"
#define LIBAVCODEC_VERSION_MINOR 36
#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_MICRO 101
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \