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avcodec/mpeg4videoenc: Split writing blocks into intra and inter

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These are sufficiently different to warrant their own functions;
in particular, the earlier code had two callsites for the actual
"write block" function, one for intra and one for inter, yet
the "write block" function nevertheless performed a check
(that the compiler can't optimize away) for whether the current
MB is intra or not.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt
2025-05-18 21:14:54 +02:00
parent f7bd2a5af8
commit 7267e4dab8
1 changed files with 43 additions and 47 deletions
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80
libavcodec/mpeg4videoenc.c
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@ -293,37 +293,18 @@ static inline void mpeg4_encode_dc(PutBitContext *s, int level, int n)
}
/**
* Encode an 8x8 block.
* @param n block index (0-3 are luma, 4-5 are chroma)
* Encode the AC coefficients of an 8x8 block.
*/
static inline void mpeg4_encode_block(const MPVEncContext *const s,
const int16_t *block, int n, int intra_dc,
const uint8_t *scan_table, PutBitContext *dc_pb,
PutBitContext *ac_pb)
static inline void mpeg4_encode_ac_coeffs(const int16_t block[64],
const int last_index, int i,
const uint8_t *const scan_table,
PutBitContext *const ac_pb,
const uint32_t *const bits_tab,
const uint8_t *const len_tab)
{
int i, last_non_zero;
const uint32_t *bits_tab;
const uint8_t *len_tab;
const int last_index = s->c.block_last_index[n];
if (s->c.mb_intra) { // Note gcc (3.2.1 at least) will optimize this away
/* MPEG-4 based DC predictor */
mpeg4_encode_dc(dc_pb, intra_dc, n);
if (last_index < 1)
return;
i = 1;
bits_tab = uni_mpeg4_intra_rl_bits;
len_tab = uni_mpeg4_intra_rl_len;
} else {
if (last_index < 0)
return;
i = 0;
bits_tab = uni_mpeg4_inter_rl_bits;
len_tab = uni_mpeg4_inter_rl_len;
}
int last_non_zero = i - 1;
/* AC coefs */
last_non_zero = i - 1;
for (; i < last_index; i++) {
int level = block[scan_table[i]];
if (level) {
@ -357,25 +338,40 @@ static inline void mpeg4_encode_block(const MPVEncContext *const s,
}
}
static inline void mpeg4_encode_blocks(MPVEncContext *const s,
static void mpeg4_encode_blocks_inter(MPVEncContext *const s,
const int16_t block[6][64],
PutBitContext *ac_pb)
{
/* encode each block */
for (int n = 0; n < 6; ++n) {
const int last_index = s->c.block_last_index[n];
if (last_index < 0)
continue;
mpeg4_encode_ac_coeffs(block[n], last_index, 0,
s->c.intra_scantable.permutated, ac_pb,
uni_mpeg4_inter_rl_bits, uni_mpeg4_inter_rl_len);
}
}
static void mpeg4_encode_blocks_intra(MPVEncContext *const s,
const int16_t block[6][64],
const int intra_dc[6],
const uint8_t * const *scan_table,
PutBitContext *dc_pb,
PutBitContext *ac_pb)
{
int i;
/* encode each block */
for (int n = 0; n < 6; ++n) {
mpeg4_encode_dc(dc_pb, intra_dc[n], n);
if (scan_table) {
/* encode each block */
for (i = 0; i < 6; i++)
mpeg4_encode_block(s, block[i], i,
intra_dc[i], scan_table[i], dc_pb, ac_pb);
} else {
/* encode each block */
for (i = 0; i < 6; i++)
mpeg4_encode_block(s, block[i], i, 0,
s->c.intra_scantable.permutated, dc_pb, ac_pb);
const int last_index = s->c.block_last_index[n];
if (last_index <= 0)
continue;
mpeg4_encode_ac_coeffs(block[n], last_index, 1,
scan_table[n], ac_pb,
uni_mpeg4_intra_rl_bits, uni_mpeg4_intra_rl_len);
}
}
@ -565,7 +561,7 @@ static void mpeg4_encode_mb(MPVEncContext *const s, int16_t block[][64],
if (interleaved_stats)
s->mv_bits += get_bits_diff(s);
mpeg4_encode_blocks(s, block, NULL, NULL, NULL, &s->pb);
mpeg4_encode_blocks_inter(s, block, &s->pb);
if (interleaved_stats)
s->p_tex_bits += get_bits_diff(s);
@ -728,7 +724,7 @@ static void mpeg4_encode_mb(MPVEncContext *const s, int16_t block[][64],
if (interleaved_stats)
s->mv_bits += get_bits_diff(s);
mpeg4_encode_blocks(s, block, NULL, NULL, NULL, tex_pb);
mpeg4_encode_blocks_inter(s, block, tex_pb);
if (interleaved_stats)
s->p_tex_bits += get_bits_diff(s);
@ -790,7 +786,7 @@ static void mpeg4_encode_mb(MPVEncContext *const s, int16_t block[][64],
if (interleaved_stats)
s->misc_bits += get_bits_diff(s);
mpeg4_encode_blocks(s, block, dc_diff, scan_table, dc_pb, tex_pb);
mpeg4_encode_blocks_intra(s, block, dc_diff, scan_table, dc_pb, tex_pb);
if (interleaved_stats)
s->i_tex_bits += get_bits_diff(s);