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ffmpeg.wasm-core
Commit 0404ec61 authored by Diego Biurrun's avatar Diego Biurrun
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h261: cosmetics: Move functions to avoid forward declarations

parent b78f81c8
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Showing with 161 additions and 166 deletions
libavcodec/h261dec.c
View file @ 0404ec61
......@@ -44,8 +44,6 @@ static VLC h261_mtype_vlc;
static VLC h261_mv_vlc;
static VLC h261_cbp_vlc;
static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded);
static av_cold void h261_decode_init_vlc(H261Context *h)
{
static int done = 0;
......@@ -246,6 +244,94 @@ static int decode_mv_component(GetBitContext *gb, int v)
return v;
}
/**
* Decode a macroblock.
* @return <0 if an error occurred
*/
static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
{
MpegEncContext *const s = &h->s;
int code, level, i, j, run;
RLTable *rl = &h261_rl_tcoeff;
const uint8_t *scan_table;
/* For the variable length encoding there are two code tables, one being
* used for the first transmitted LEVEL in INTER, INTER + MC and
* INTER + MC + FIL blocks, the second for all other LEVELs except the
* first one in INTRA blocks which is fixed length coded with 8 bits.
* NOTE: The two code tables only differ in one VLC so we handle that
* manually. */
scan_table = s->intra_scantable.permutated;
if (s->mb_intra) {
/* DC coef */
level = get_bits(&s->gb, 8);
// 0 (00000000b) and -128 (10000000b) are FORBIDDEN
if ((level & 0x7F) == 0) {
av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n",
level, s->mb_x, s->mb_y);
return -1;
}
/* The code 1000 0000 is not used, the reconstruction level of 1024
* being coded as 1111 1111. */
if (level == 255)
level = 128;
block[0] = level;
i = 1;
} else if (coded) {
// Run Level Code
// EOB Not possible for first level when cbp is available (that's why the table is different)
// 0 1 1s
// * * 0*
int check = show_bits(&s->gb, 2);
i = 0;
if (check & 0x2) {
skip_bits(&s->gb, 2);
block[0] = (check & 0x1) ? -1 : 1;
i = 1;
}
} else {
i = 0;
}
if (!coded) {
s->block_last_index[n] = i - 1;
return 0;
}
for (;;) {
code = get_vlc2(&s->gb, rl->vlc.table, TCOEFF_VLC_BITS, 2);
if (code < 0) {
av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
s->mb_x, s->mb_y);
return -1;
}
if (code == rl->n) {
/* escape */
/* The remaining combinations of (run, level) are encoded with a
* 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
* level. */
run = get_bits(&s->gb, 6);
level = get_sbits(&s->gb, 8);
} else if (code == 0) {
break;
} else {
run = rl->table_run[code];
level = rl->table_level[code];
if (get_bits1(&s->gb))
level = -level;
}
i += run;
if (i >= 64) {
av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
s->mb_x, s->mb_y);
return -1;
}
j = scan_table[i];
block[j] = level;
i++;
}
s->block_last_index[n] = i - 1;
return 0;
}
static int h261_decode_mb(H261Context *h)
{
MpegEncContext *const s = &h->s;
......@@ -353,94 +439,6 @@ intra:
return SLICE_OK;
}
/**
* Decode a macroblock.
* @return <0 if an error occurred
*/
static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
{
MpegEncContext *const s = &h->s;
int code, level, i, j, run;
RLTable *rl = &h261_rl_tcoeff;
const uint8_t *scan_table;
/* For the variable length encoding there are two code tables, one being
* used for the first transmitted LEVEL in INTER, INTER + MC and
* INTER + MC + FIL blocks, the second for all other LEVELs except the
* first one in INTRA blocks which is fixed length coded with 8 bits.
* NOTE: The two code tables only differ in one VLC so we handle that
* manually. */
scan_table = s->intra_scantable.permutated;
if (s->mb_intra) {
/* DC coef */
level = get_bits(&s->gb, 8);
// 0 (00000000b) and -128 (10000000b) are FORBIDDEN
if ((level & 0x7F) == 0) {
av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n",
level, s->mb_x, s->mb_y);
return -1;
}
/* The code 1000 0000 is not used, the reconstruction level of 1024
* being coded as 1111 1111. */
if (level == 255)
level = 128;
block[0] = level;
i = 1;
} else if (coded) {
// Run Level Code
// EOB Not possible for first level when cbp is available (that's why the table is different)
// 0 1 1s
// * * 0*
int check = show_bits(&s->gb, 2);
i = 0;
if (check & 0x2) {
skip_bits(&s->gb, 2);
block[0] = (check & 0x1) ? -1 : 1;
i = 1;
}
} else {
i = 0;
}
if (!coded) {
s->block_last_index[n] = i - 1;
return 0;
}
for (;;) {
code = get_vlc2(&s->gb, rl->vlc.table, TCOEFF_VLC_BITS, 2);
if (code < 0) {
av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
s->mb_x, s->mb_y);
return -1;
}
if (code == rl->n) {
/* escape */
/* The remaining combinations of (run, level) are encoded with a
* 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
* level. */
run = get_bits(&s->gb, 6);
level = get_sbits(&s->gb, 8);
} else if (code == 0) {
break;
} else {
run = rl->table_run[code];
level = rl->table_level[code];
if (get_bits1(&s->gb))
level = -level;
}
i += run;
if (i >= 64) {
av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
s->mb_x, s->mb_y);
return -1;
}
j = scan_table[i];
block[j] = level;
i++;
}
s->block_last_index[n] = i - 1;
return 0;
}
/**
* Decode the H.261 picture header.
* @return <0 if no startcode found
......
libavcodec/h261enc.c
View file @ 0404ec61
......@@ -31,9 +31,6 @@
#include "h261.h"
#include "h261data.h"
static void h261_encode_block(H261Context *h, int16_t *block,
int n);
int ff_h261_get_picture_format(int width, int height)
{
// QCIF
......@@ -155,6 +152,79 @@ static inline int get_cbp(MpegEncContext *s, int16_t block[6][64])
return cbp;
}
/**
* Encode an 8x8 block.
* @param block the 8x8 block
* @param n block index (0-3 are luma, 4-5 are chroma)
*/
static void h261_encode_block(H261Context *h, int16_t *block, int n)
{
MpegEncContext *const s = &h->s;
int level, run, i, j, last_index, last_non_zero, sign, slevel, code;
RLTable *rl;
rl = &h261_rl_tcoeff;
if (s->mb_intra) {
/* DC coef */
level = block[0];
/* 255 cannot be represented, so we clamp */
if (level > 254) {
level = 254;
block[0] = 254;
}
/* 0 cannot be represented also */
else if (level < 1) {
level = 1;
block[0] = 1;
}
if (level == 128)
put_bits(&s->pb, 8, 0xff);
else
put_bits(&s->pb, 8, level);
i = 1;
} else if ((block[0] == 1 || block[0] == -1) &&
(s->block_last_index[n] > -1)) {
// special case
put_bits(&s->pb, 2, block[0] > 0 ? 2 : 3);
i = 1;
} else {
i = 0;
}
/* AC coefs */
last_index = s->block_last_index[n];
last_non_zero = i - 1;
for (; i <= last_index; i++) {
j = s->intra_scantable.permutated[i];
level = block[j];
if (level) {
run = i - last_non_zero - 1;
sign = 0;
slevel = level;
if (level < 0) {
sign = 1;
level = -level;
}
code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/,
run, level);
if (run == 0 && level < 16)
code += 1;
put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
if (code == rl->n) {
put_bits(&s->pb, 6, run);
assert(slevel != 0);
assert(level <= 127);
put_sbits(&s->pb, 8, slevel);
} else {
put_bits(&s->pb, 1, sign);
}
last_non_zero = i;
}
}
if (last_index > -1)
put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]); // EOB
}
void ff_h261_encode_mb(MpegEncContext *s, int16_t block[6][64],
int motion_x, int motion_y)
{
......@@ -252,79 +322,6 @@ void ff_h261_encode_init(MpegEncContext *s)
s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
}
/**
* Encode an 8x8 block.
* @param block the 8x8 block
* @param n block index (0-3 are luma, 4-5 are chroma)
*/
static void h261_encode_block(H261Context *h, int16_t *block, int n)
{
MpegEncContext *const s = &h->s;
int level, run, i, j, last_index, last_non_zero, sign, slevel, code;
RLTable *rl;
rl = &h261_rl_tcoeff;
if (s->mb_intra) {
/* DC coef */
level = block[0];
/* 255 cannot be represented, so we clamp */
if (level > 254) {
level = 254;
block[0] = 254;
}
/* 0 cannot be represented also */
else if (level < 1) {
level = 1;
block[0] = 1;
}
if (level == 128)
put_bits(&s->pb, 8, 0xff);
else
put_bits(&s->pb, 8, level);
i = 1;
} else if ((block[0] == 1 || block[0] == -1) &&
(s->block_last_index[n] > -1)) {
// special case
put_bits(&s->pb, 2, block[0] > 0 ? 2 : 3);
i = 1;
} else {
i = 0;
}
/* AC coefs */
last_index = s->block_last_index[n];
last_non_zero = i - 1;
for (; i <= last_index; i++) {
j = s->intra_scantable.permutated[i];
level = block[j];
if (level) {
run = i - last_non_zero - 1;
sign = 0;
slevel = level;
if (level < 0) {
sign = 1;
level = -level;
}
code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/,
run, level);
if (run == 0 && level < 16)
code += 1;
put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
if (code == rl->n) {
put_bits(&s->pb, 6, run);
assert(slevel != 0);
assert(level <= 127);
put_sbits(&s->pb, 8, slevel);
} else {
put_bits(&s->pb, 1, sign);
}
last_non_zero = i;
}
}
if (last_index > -1)
put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]); // EOB
}
FF_MPV_GENERIC_CLASS(h261)
AVCodec ff_h261_encoder = {
......
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