#include "mpegvideo.h"
#include "h263.h"
#include "h261.h"
-#include "h261data.h"
+#include "internal.h"
#define H261_MBA_VLC_BITS 9
#define H261_MTYPE_VLC_BITS 6
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;
if (!done) {
done = 1;
INIT_VLC_STATIC(&h261_mba_vlc, H261_MBA_VLC_BITS, 35,
- h261_mba_bits, 1, 1,
- h261_mba_code, 1, 1, 662);
+ ff_h261_mba_bits, 1, 1,
+ ff_h261_mba_code, 1, 1, 662);
INIT_VLC_STATIC(&h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
- h261_mtype_bits, 1, 1,
- h261_mtype_code, 1, 1, 80);
+ ff_h261_mtype_bits, 1, 1,
+ ff_h261_mtype_code, 1, 1, 80);
INIT_VLC_STATIC(&h261_mv_vlc, H261_MV_VLC_BITS, 17,
- &h261_mv_tab[0][1], 2, 1,
- &h261_mv_tab[0][0], 2, 1, 144);
+ &ff_h261_mv_tab[0][1], 2, 1,
+ &ff_h261_mv_tab[0][0], 2, 1, 144);
INIT_VLC_STATIC(&h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
- &h261_cbp_tab[0][1], 2, 1,
- &h261_cbp_tab[0][0], 2, 1, 512);
- ff_init_rl(&h261_rl_tcoeff, ff_h261_rl_table_store);
- INIT_VLC_RL(h261_rl_tcoeff, 552);
+ &ff_h261_cbp_tab[0][1], 2, 1,
+ &ff_h261_cbp_tab[0][0], 2, 1, 512);
+ INIT_VLC_RL(ff_h261_rl_tcoeff, 552);
}
}
avctx->pix_fmt = AV_PIX_FMT_YUV420P;
s->codec_id = avctx->codec->id;
+ ff_h261_common_init();
h261_decode_init_vlc(h);
h->gob_start_code_skipped = 0;
* Decode the group of blocks / video packet header.
* @return <0 if no resync found
*/
-static int ff_h261_resync(H261Context *h)
+static int h261_resync(H261Context *h)
{
MpegEncContext *const s = &h->s;
int left, ret;
return 0;
}
+static const int mvmap[17] = {
+ 0, -1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15, -16
+};
+
static int decode_mv_component(GetBitContext *gb, int v)
{
int mv_diff = get_vlc2(gb, h261_mv_vlc.table, H261_MV_VLC_BITS, 2);
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 = &ff_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;
// Read mtype
h->mtype = get_vlc2(&s->gb, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2);
- h->mtype = h261_mtype_map[h->mtype];
+ if (h->mtype < 0 || h->mtype >= FF_ARRAY_ELEMS(ff_h261_mtype_map)) {
+ av_log(s->avctx, AV_LOG_ERROR, "Invalid mtype index %d\n",
+ h->mtype);
+ return SLICE_ERROR;
+ }
+ h->mtype = ff_h261_mtype_map[h->mtype];
// Read mquant
if (IS_QUANT(h->mtype))
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
s->picture_number = (s->picture_number & ~31) + i;
s->avctx->time_base = (AVRational) { 1001, 30000 };
- s->current_picture.f.pts = s->picture_number;
/* PTYPE starts here */
skip_bits1(&s->gb); /* split screen off */
s->parse_context = pc;
}
if (!s->context_initialized) {
- avcodec_set_dimensions(avctx, s->width, s->height);
+ ret = ff_set_dimensions(avctx, s->width, s->height);
+ if (ret < 0)
+ return ret;
goto retry;
}
s->mb_y = 0;
while (h->gob_number < (s->mb_height == 18 ? 12 : 5)) {
- if (ff_h261_resync(h) < 0)
+ if (h261_resync(h) < 0)
break;
h261_decode_gob(h);
}
AVCodec ff_h261_decoder = {
.name = "h261",
+ .long_name = NULL_IF_CONFIG_SMALL("H.261"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_H261,
.priv_data_size = sizeof(H261Context),
.close = h261_decode_end,
.decode = h261_decode_frame,
.capabilities = CODEC_CAP_DR1,
- .long_name = NULL_IF_CONFIG_SMALL("H.261"),
};
projects / ffmpeg / blobdiff