diff options
Diffstat (limited to 'libavcodec/h261dec.c')
-rw-r--r-- | libavcodec/h261dec.c | 92 |
1 files changed, 47 insertions, 45 deletions
diff --git a/libavcodec/h261dec.c b/libavcodec/h261dec.c index 9a323ec..b08598e 100644 --- a/libavcodec/h261dec.c +++ b/libavcodec/h261dec.c @@ -26,12 +26,14 @@ */ #include "avcodec.h" +#include "bitstream.h" #include "mpeg_er.h" #include "mpegutils.h" #include "mpegvideo.h" #include "h263.h" #include "h261.h" #include "internal.h" +#include "vlc.h" #define H261_MBA_VLC_BITS 9 #define H261_MTYPE_VLC_BITS 6 @@ -103,18 +105,18 @@ static int h261_decode_gob_header(H261Context *h) if (!h->gob_start_code_skipped) { /* Check for GOB Start Code */ - val = show_bits(&s->gb, 15); + val = bitstream_peek(&s->bc, 15); if (val) return -1; /* We have a GBSC */ - skip_bits(&s->gb, 16); + bitstream_skip(&s->bc, 16); } h->gob_start_code_skipped = 0; - h->gob_number = get_bits(&s->gb, 4); /* GN */ - s->qscale = get_bits(&s->gb, 5); /* GQUANT */ + h->gob_number = bitstream_read(&s->bc, 4); /* GN */ + s->qscale = bitstream_read(&s->bc, 5); /* GQUANT */ /* Check if gob_number is valid */ if (s->mb_height == 18) { // CIF @@ -127,8 +129,8 @@ static int h261_decode_gob_header(H261Context *h) } /* GEI */ - while (get_bits1(&s->gb) != 0) - skip_bits(&s->gb, 8); + while (bitstream_read_bit(&s->bc) != 0) + bitstream_skip(&s->bc, 8); if (s->qscale == 0) { av_log(s->avctx, AV_LOG_ERROR, "qscale has forbidden 0 value\n"); @@ -160,27 +162,27 @@ static int h261_resync(H261Context *h) if (ret >= 0) return 0; } else { - if (show_bits(&s->gb, 15) == 0) { + if (bitstream_peek(&s->bc, 15) == 0) { ret = h261_decode_gob_header(h); if (ret >= 0) return 0; } // OK, it is not where it is supposed to be ... - s->gb = s->last_resync_gb; - align_get_bits(&s->gb); - left = get_bits_left(&s->gb); + s->bc = s->last_resync_bc; + bitstream_align(&s->bc); + left = bitstream_bits_left(&s->bc); for (; left > 15 + 1 + 4 + 5; left -= 8) { - if (show_bits(&s->gb, 15) == 0) { - GetBitContext bak = s->gb; + if (bitstream_peek(&s->bc, 15) == 0) { + BitstreamContext bak = s->bc; ret = h261_decode_gob_header(h); if (ret >= 0) return 0; - s->gb = bak; + s->bc = bak; } - skip_bits(&s->gb, 8); + bitstream_skip(&s->bc, 8); } } @@ -228,9 +230,9 @@ 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) +static int decode_mv_component(BitstreamContext *bc, int v) { - int mv_diff = get_vlc2(gb, h261_mv_vlc.table, H261_MV_VLC_BITS, 2); + int mv_diff = bitstream_read_vlc(bc, h261_mv_vlc.table, H261_MV_VLC_BITS, 2); /* check if mv_diff is valid */ if (mv_diff < 0) @@ -238,7 +240,7 @@ static int decode_mv_component(GetBitContext *gb, int v) mv_diff = mvmap[mv_diff]; - if (mv_diff && !get_bits1(gb)) + if (mv_diff && !bitstream_read_bit(bc)) mv_diff = -mv_diff; v += mv_diff; @@ -270,7 +272,7 @@ static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded) scan_table = s->intra_scantable.permutated; if (s->mb_intra) { /* DC coef */ - level = get_bits(&s->gb, 8); + level = bitstream_read(&s->bc, 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", @@ -288,10 +290,10 @@ static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded) // 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); + int check = bitstream_peek(&s->bc, 2); i = 0; if (check & 0x2) { - skip_bits(&s->gb, 2); + bitstream_skip(&s->bc, 2); block[0] = (check & 0x1) ? -1 : 1; i = 1; } @@ -303,7 +305,7 @@ static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded) return 0; } for (;;) { - code = get_vlc2(&s->gb, rl->vlc.table, TCOEFF_VLC_BITS, 2); + code = bitstream_read_vlc(&s->bc, 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); @@ -314,14 +316,14 @@ static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded) /* 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); + run = bitstream_read(&s->bc, 6); + level = bitstream_read_signed(&s->bc, 8); } else if (code == 0) { break; } else { run = rl->table_run[code]; level = rl->table_level[code]; - if (get_bits1(&s->gb)) + if (bitstream_read_bit(&s->bc)) level = -level; } i += run; @@ -346,8 +348,8 @@ static int h261_decode_mb(H261Context *h) cbp = 63; // Read mba do { - h->mba_diff = get_vlc2(&s->gb, h261_mba_vlc.table, - H261_MBA_VLC_BITS, 2); + h->mba_diff = bitstream_read_vlc(&s->bc, h261_mba_vlc.table, + H261_MBA_VLC_BITS, 2); /* Check for slice end */ /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */ @@ -358,7 +360,7 @@ static int h261_decode_mb(H261Context *h) } while (h->mba_diff == MBA_STUFFING); // stuffing if (h->mba_diff < 0) { - if (get_bits_left(&s->gb) <= 7) + if (bitstream_bits_left(&s->bc) <= 7) return SLICE_END; av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y); @@ -378,7 +380,7 @@ static int h261_decode_mb(H261Context *h) ff_update_block_index(s); // Read mtype - h->mtype = get_vlc2(&s->gb, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2); + h->mtype = bitstream_read_vlc(&s->bc, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2); 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); @@ -388,7 +390,7 @@ static int h261_decode_mb(H261Context *h) // Read mquant if (IS_QUANT(h->mtype)) - ff_set_qscale(s, get_bits(&s->gb, 5)); + ff_set_qscale(s, bitstream_read(&s->bc, 5)); s->mb_intra = IS_INTRA4x4(h->mtype); @@ -408,8 +410,8 @@ static int h261_decode_mb(H261Context *h) h->current_mv_y = 0; } - h->current_mv_x = decode_mv_component(&s->gb, h->current_mv_x); - h->current_mv_y = decode_mv_component(&s->gb, h->current_mv_y); + h->current_mv_x = decode_mv_component(&s->bc, h->current_mv_x); + h->current_mv_y = decode_mv_component(&s->bc, h->current_mv_y); } else { h->current_mv_x = 0; h->current_mv_y = 0; @@ -417,7 +419,7 @@ static int h261_decode_mb(H261Context *h) // Read cbp if (HAS_CBP(h->mtype)) - cbp = get_vlc2(&s->gb, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1; + cbp = bitstream_read_vlc(&s->bc, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1; if (s->mb_intra) { s->current_picture.mb_type[xy] = MB_TYPE_INTRA; @@ -460,8 +462,8 @@ static int h261_decode_picture_header(H261Context *h) int format, i; uint32_t startcode = 0; - for (i = get_bits_left(&s->gb); i > 24; i -= 1) { - startcode = ((startcode << 1) | get_bits(&s->gb, 1)) & 0x000FFFFF; + for (i = bitstream_bits_left(&s->bc); i > 24; i -= 1) { + startcode = ((startcode << 1) | bitstream_read(&s->bc, 1)) & 0x000FFFFF; if (startcode == 0x10) break; @@ -473,7 +475,7 @@ static int h261_decode_picture_header(H261Context *h) } /* temporal reference */ - i = get_bits(&s->gb, 5); /* picture timestamp */ + i = bitstream_read(&s->bc, 5); /* picture timestamp */ if (i < (s->picture_number & 31)) i += 32; s->picture_number = (s->picture_number & ~31) + i; @@ -481,11 +483,11 @@ static int h261_decode_picture_header(H261Context *h) s->avctx->framerate = (AVRational) { 30000, 1001 }; /* PTYPE starts here */ - skip_bits1(&s->gb); /* split screen off */ - skip_bits1(&s->gb); /* camera off */ - skip_bits1(&s->gb); /* freeze picture release off */ + bitstream_skip(&s->bc, 1); /* split screen off */ + bitstream_skip(&s->bc, 1); /* camera off */ + bitstream_skip(&s->bc, 1); /* freeze picture release off */ - format = get_bits1(&s->gb); + format = bitstream_read_bit(&s->bc); // only 2 formats possible if (format == 0) { // QCIF @@ -502,12 +504,12 @@ static int h261_decode_picture_header(H261Context *h) s->mb_num = s->mb_width * s->mb_height; - skip_bits1(&s->gb); /* still image mode off */ - skip_bits1(&s->gb); /* Reserved */ + bitstream_skip(&s->bc, 1); /* still image mode off */ + bitstream_skip(&s->bc, 1); /* Reserved */ /* PEI */ - while (get_bits1(&s->gb) != 0) - skip_bits(&s->gb, 8); + while (bitstream_read_bit(&s->bc) != 0) + bitstream_skip(&s->bc, 8); /* H.261 has no I-frames, but if we pass AV_PICTURE_TYPE_I for the first * frame, the codec crashes if it does not contain all I-blocks @@ -552,7 +554,7 @@ static int h261_decode_gob(H261Context *h) */ static int get_consumed_bytes(MpegEncContext *s, int buf_size) { - int pos = get_bits_count(&s->gb) >> 3; + int pos = bitstream_tell(&s->bc) >> 3; if (pos == 0) pos = 1; // avoid infinite loops (i doubt that is needed but ...) if (pos + 10 > buf_size) @@ -577,7 +579,7 @@ static int h261_decode_frame(AVCodecContext *avctx, void *data, h->gob_start_code_skipped = 0; retry: - init_get_bits(&s->gb, buf, buf_size * 8); + bitstream_init8(&s->bc, buf, buf_size); if (!s->context_initialized) // we need the IDCT permutation for reading a custom matrix |