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truehd_core: Use byte offsets instead of bit offsets

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Words of 16 bit are the unit for TrueHD's size and offset fields;
in particular the sizes of the high-level structures of TrueHD are
always a multiple of a byte; yet truehd_core unnecessarily used
bit offsets at several places. This has been changed.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2019-07-06 16:18:03 +02:00 committed by Paul B Mahol
parent 2275e70569
commit 836065b27a
1 changed files with 11 additions and 9 deletions
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20
libavcodec/truehd_core_bsf.c
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@ -45,7 +45,7 @@ static int truehd_core_filter(AVBSFContext *ctx, AVPacket *out)
int ret, i, last_offset = 0;
int in_size, out_size;
int have_header = 0;
int substream_bits = 0;
int substream_bytes = 0;
int end;
ret = ff_bsf_get_packet(ctx, &in);
@ -85,30 +85,32 @@ static int truehd_core_filter(AVBSFContext *ctx, AVPacket *out)
units[i].offset = get_bits(&gbc, 12);
if (i < 3) {
last_offset = units[i].offset * 2;
substream_bits += 16;
substream_bytes += 2;
}
if (units[i].bits[0]) {
units[i].optional = get_bits(&gbc, 16);
if (i < 3)
substream_bits += 16;
substream_bytes += 2;
}
}
end = get_bits_count(&gbc);
end = get_bits_count(&gbc) >> 3;
out_size = ((end + 7) >> 3) + 4 + last_offset;
out_size = end + 4 + last_offset;
if (out_size < in_size) {
int bpos = 0, reduce = (end - have_header * 28 * 8 - substream_bits) >> 4;
int bpos = 0, reduce = end - have_header * 28 - substream_bytes;
uint16_t parity_nibble, dts = AV_RB16(in->data + 2);
uint16_t auheader;
av_assert1(reduce % 2 == 0);
ret = av_new_packet(out, out_size);
if (ret < 0)
goto fail;
AV_WB16(out->data + 2, dts);
parity_nibble = dts;
out->size -= reduce * 2;
out->size -= reduce;
parity_nibble ^= out->size / 2;
if (have_header) {
@ -146,8 +148,8 @@ static int truehd_core_filter(AVBSFContext *ctx, AVPacket *out)
parity_nibble &= 0xF;
memcpy(out->data + have_header * 28 + 4 + bpos,
in->data + 4 + (end >> 3),
out_size - (4 + (end >> 3)));
in->data + 4 + end,
out_size - (4 + end));
auheader = (parity_nibble ^ 0xF) << 12;
auheader |= (out->size / 2) & 0x0fff;
AV_WB16(out->data, auheader);