diff options
Diffstat (limited to 'ffmpeg/libavcodec/h261dec.c')
| -rw-r--r-- | ffmpeg/libavcodec/h261dec.c | 668 |
1 files changed, 0 insertions, 668 deletions
diff --git a/ffmpeg/libavcodec/h261dec.c b/ffmpeg/libavcodec/h261dec.c deleted file mode 100644 index 49f1b4a..0000000 --- a/ffmpeg/libavcodec/h261dec.c +++ /dev/null @@ -1,668 +0,0 @@ -/* - * H261 decoder - * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> - * Copyright (c) 2004 Maarten Daniels - * - * This file is part of FFmpeg. - * - * FFmpeg is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * FFmpeg is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -/** - * @file - * H.261 decoder. - */ - -#include "libavutil/avassert.h" -#include "avcodec.h" -#include "mpegvideo.h" -#include "h263.h" -#include "h261.h" -#include "internal.h" - -#define H261_MBA_VLC_BITS 9 -#define H261_MTYPE_VLC_BITS 6 -#define H261_MV_VLC_BITS 7 -#define H261_CBP_VLC_BITS 9 -#define TCOEFF_VLC_BITS 9 -#define MBA_STUFFING 33 -#define MBA_STARTCODE 34 - -static VLC h261_mba_vlc; -static VLC h261_mtype_vlc; -static VLC h261_mv_vlc; -static VLC h261_cbp_vlc; - -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, - ff_h261_mba_bits, 1, 1, - ff_h261_mba_code, 1, 1, 662); - INIT_VLC_STATIC(&h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10, - ff_h261_mtype_bits, 1, 1, - ff_h261_mtype_code, 1, 1, 80); - INIT_VLC_STATIC(&h261_mv_vlc, H261_MV_VLC_BITS, 17, - &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, - &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); - } -} - -static av_cold int h261_decode_init(AVCodecContext *avctx) -{ - H261Context *h = avctx->priv_data; - MpegEncContext *const s = &h->s; - - // set defaults - ff_MPV_decode_defaults(s); - s->avctx = avctx; - s->width = s->avctx->coded_width; - s->height = s->avctx->coded_height; - s->codec_id = s->avctx->codec->id; - s->out_format = FMT_H261; - s->low_delay = 1; - 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; - - return 0; -} - -/** - * Decode the group of blocks header or slice header. - * @return <0 if an error occurred - */ -static int h261_decode_gob_header(H261Context *h) -{ - unsigned int val; - MpegEncContext *const s = &h->s; - - if (!h->gob_start_code_skipped) { - /* Check for GOB Start Code */ - val = show_bits(&s->gb, 15); - if (val) - return -1; - - /* We have a GBSC */ - skip_bits(&s->gb, 16); - } - - h->gob_start_code_skipped = 0; - - h->gob_number = get_bits(&s->gb, 4); /* GN */ - s->qscale = get_bits(&s->gb, 5); /* GQUANT */ - - /* Check if gob_number is valid */ - if (s->mb_height == 18) { // CIF - if ((h->gob_number <= 0) || (h->gob_number > 12)) - return -1; - } else { // QCIF - if ((h->gob_number != 1) && (h->gob_number != 3) && - (h->gob_number != 5)) - return -1; - } - - /* GEI */ - if (skip_1stop_8data_bits(&s->gb) < 0) - return AVERROR_INVALIDDATA; - - if (s->qscale == 0) { - av_log(s->avctx, AV_LOG_ERROR, "qscale has forbidden 0 value\n"); - if (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT)) - return -1; - } - - /* For the first transmitted macroblock in a GOB, MBA is the absolute - * address. For subsequent macroblocks, MBA is the difference between - * the absolute addresses of the macroblock and the last transmitted - * macroblock. */ - h->current_mba = 0; - h->mba_diff = 0; - - return 0; -} - -/** - * Decode the group of blocks / video packet header. - * @return <0 if no resync found - */ -static int h261_resync(H261Context *h) -{ - MpegEncContext *const s = &h->s; - int left, ret; - - if (h->gob_start_code_skipped) { - ret = h261_decode_gob_header(h); - if (ret >= 0) - return 0; - } else { - if (show_bits(&s->gb, 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); - - for (; left > 15 + 1 + 4 + 5; left -= 8) { - if (show_bits(&s->gb, 15) == 0) { - GetBitContext bak = s->gb; - - ret = h261_decode_gob_header(h); - if (ret >= 0) - return 0; - - s->gb = bak; - } - skip_bits(&s->gb, 8); - } - } - - return -1; -} - -/** - * Decode skipped macroblocks. - * @return 0 - */ -static int h261_decode_mb_skipped(H261Context *h, int mba1, int mba2) -{ - MpegEncContext *const s = &h->s; - int i; - - s->mb_intra = 0; - - for (i = mba1; i < mba2; i++) { - int j, xy; - - s->mb_x = ((h->gob_number - 1) % 2) * 11 + i % 11; - s->mb_y = ((h->gob_number - 1) / 2) * 3 + i / 11; - xy = s->mb_x + s->mb_y * s->mb_stride; - ff_init_block_index(s); - ff_update_block_index(s); - - for (j = 0; j < 6; j++) - s->block_last_index[j] = -1; - - s->mv_dir = MV_DIR_FORWARD; - s->mv_type = MV_TYPE_16X16; - s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0; - s->mv[0][0][0] = 0; - s->mv[0][0][1] = 0; - s->mb_skipped = 1; - h->mtype &= ~MB_TYPE_H261_FIL; - - ff_MPV_decode_mb(s, s->block); - } - - 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); - - /* check if mv_diff is valid */ - if (mv_diff < 0) - return v; - - mv_diff = mvmap[mv_diff]; - - if (mv_diff && !get_bits1(gb)) - mv_diff = -mv_diff; - - v += mv_diff; - if (v <= -16) - v += 32; - else if (v >= 16) - v -= 32; - - 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; - int i, cbp, xy; - - cbp = 63; - // Read mba - do { - h->mba_diff = get_vlc2(&s->gb, 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 */ - if (h->mba_diff == MBA_STARTCODE) { // start code - h->gob_start_code_skipped = 1; - return SLICE_END; - } - } while (h->mba_diff == MBA_STUFFING); // stuffing - - if (h->mba_diff < 0) { - if (get_bits_left(&s->gb) <= 7) - return SLICE_END; - - av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y); - return SLICE_ERROR; - } - - h->mba_diff += 1; - h->current_mba += h->mba_diff; - - if (h->current_mba > MBA_STUFFING) - return SLICE_ERROR; - - s->mb_x = ((h->gob_number - 1) % 2) * 11 + ((h->current_mba - 1) % 11); - s->mb_y = ((h->gob_number - 1) / 2) * 3 + ((h->current_mba - 1) / 11); - xy = s->mb_x + s->mb_y * s->mb_stride; - ff_init_block_index(s); - ff_update_block_index(s); - - // Read mtype - h->mtype = get_vlc2(&s->gb, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2); - if (h->mtype < 0) { - av_log(s->avctx, AV_LOG_ERROR, "Invalid mtype index %d\n", - h->mtype); - return SLICE_ERROR; - } - av_assert0(h->mtype < FF_ARRAY_ELEMS(ff_h261_mtype_map)); - h->mtype = ff_h261_mtype_map[h->mtype]; - - // Read mquant - if (IS_QUANT(h->mtype)) - ff_set_qscale(s, get_bits(&s->gb, 5)); - - s->mb_intra = IS_INTRA4x4(h->mtype); - - // Read mv - if (IS_16X16(h->mtype)) { - /* Motion vector data is included for all MC macroblocks. MVD is - * obtained from the macroblock vector by subtracting the vector - * of the preceding macroblock. For this calculation the vector - * of the preceding macroblock is regarded as zero in the - * following three situations: - * 1) evaluating MVD for macroblocks 1, 12 and 23; - * 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1; - * 3) MTYPE of the previous macroblock was not MC. */ - if ((h->current_mba == 1) || (h->current_mba == 12) || - (h->current_mba == 23) || (h->mba_diff != 1)) { - h->current_mv_x = 0; - 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); - } else { - h->current_mv_x = 0; - h->current_mv_y = 0; - } - - // Read cbp - if (HAS_CBP(h->mtype)) - cbp = get_vlc2(&s->gb, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1; - - if (s->mb_intra) { - s->current_picture.mb_type[xy] = MB_TYPE_INTRA; - goto intra; - } - - //set motion vectors - s->mv_dir = MV_DIR_FORWARD; - s->mv_type = MV_TYPE_16X16; - s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0; - s->mv[0][0][0] = h->current_mv_x * 2; // gets divided by 2 in motion compensation - s->mv[0][0][1] = h->current_mv_y * 2; - -intra: - /* decode each block */ - if (s->mb_intra || HAS_CBP(h->mtype)) { - s->dsp.clear_blocks(s->block[0]); - for (i = 0; i < 6; i++) { - if (h261_decode_block(h, s->block[i], i, cbp & 32) < 0) - return SLICE_ERROR; - cbp += cbp; - } - } else { - for (i = 0; i < 6; i++) - s->block_last_index[i] = -1; - } - - ff_MPV_decode_mb(s, s->block); - - return SLICE_OK; -} - -/** - * Decode the H.261 picture header. - * @return <0 if no startcode found - */ -static int h261_decode_picture_header(H261Context *h) -{ - MpegEncContext *const s = &h->s; - 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; - - if (startcode == 0x10) - break; - } - - if (startcode != 0x10) { - av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); - return -1; - } - - /* temporal reference */ - i = get_bits(&s->gb, 5); /* picture timestamp */ - if (i < (s->picture_number & 31)) - i += 32; - s->picture_number = (s->picture_number & ~31) + i; - - s->avctx->time_base = (AVRational) { 1001, 30000 }; - - /* PTYPE starts here */ - skip_bits1(&s->gb); /* split screen off */ - skip_bits1(&s->gb); /* camera off */ - skip_bits1(&s->gb); /* freeze picture release off */ - - format = get_bits1(&s->gb); - - // only 2 formats possible - if (format == 0) { // QCIF - s->width = 176; - s->height = 144; - s->mb_width = 11; - s->mb_height = 9; - } else { // CIF - s->width = 352; - s->height = 288; - s->mb_width = 22; - s->mb_height = 18; - } - - s->mb_num = s->mb_width * s->mb_height; - - skip_bits1(&s->gb); /* still image mode off */ - skip_bits1(&s->gb); /* Reserved */ - - /* PEI */ - if (skip_1stop_8data_bits(&s->gb) < 0) - return AVERROR_INVALIDDATA; - - /* 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 - * (e.g. when a packet is lost). */ - s->pict_type = AV_PICTURE_TYPE_P; - - h->gob_number = 0; - return 0; -} - -static int h261_decode_gob(H261Context *h) -{ - MpegEncContext *const s = &h->s; - - ff_set_qscale(s, s->qscale); - - /* decode mb's */ - while (h->current_mba <= MBA_STUFFING) { - int ret; - /* DCT & quantize */ - ret = h261_decode_mb(h); - if (ret < 0) { - if (ret == SLICE_END) { - h261_decode_mb_skipped(h, h->current_mba, 33); - return 0; - } - av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", - s->mb_x + s->mb_y * s->mb_stride); - return -1; - } - - h261_decode_mb_skipped(h, - h->current_mba - h->mba_diff, - h->current_mba - 1); - } - - return -1; -} - -/** - * returns the number of bytes consumed for building the current frame - */ -static int get_consumed_bytes(MpegEncContext *s, int buf_size) -{ - int pos = get_bits_count(&s->gb) >> 3; - if (pos == 0) - pos = 1; // avoid infinite loops (i doubt that is needed but ...) - if (pos + 10 > buf_size) - pos = buf_size; // oops ;) - - return pos; -} - -static int h261_decode_frame(AVCodecContext *avctx, void *data, - int *got_frame, AVPacket *avpkt) -{ - const uint8_t *buf = avpkt->data; - int buf_size = avpkt->size; - H261Context *h = avctx->priv_data; - MpegEncContext *s = &h->s; - int ret; - AVFrame *pict = data; - - av_dlog(avctx, "*****frame %d size=%d\n", avctx->frame_number, buf_size); - av_dlog(avctx, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]); - s->flags = avctx->flags; - s->flags2 = avctx->flags2; - - h->gob_start_code_skipped = 0; - -retry: - init_get_bits(&s->gb, buf, buf_size * 8); - - if (!s->context_initialized) - // we need the IDCT permutaton for reading a custom matrix - if (ff_MPV_common_init(s) < 0) - return -1; - - ret = h261_decode_picture_header(h); - - /* skip if the header was thrashed */ - if (ret < 0) { - av_log(s->avctx, AV_LOG_ERROR, "header damaged\n"); - return -1; - } - - if (s->width != avctx->coded_width || s->height != avctx->coded_height) { - ParseContext pc = s->parse_context; // FIXME move this demuxing hack to libavformat - s->parse_context.buffer = 0; - ff_MPV_common_end(s); - s->parse_context = pc; - } - if (!s->context_initialized) { - ret = ff_set_dimensions(avctx, s->width, s->height); - if (ret < 0) - return ret; - - goto retry; - } - - // for skipping the frame - s->current_picture.f.pict_type = s->pict_type; - s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I; - - if ((avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type == AV_PICTURE_TYPE_B) || - (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type != AV_PICTURE_TYPE_I) || - avctx->skip_frame >= AVDISCARD_ALL) - return get_consumed_bytes(s, buf_size); - - if (ff_MPV_frame_start(s, avctx) < 0) - return -1; - - ff_mpeg_er_frame_start(s); - - /* decode each macroblock */ - s->mb_x = 0; - s->mb_y = 0; - - while (h->gob_number < (s->mb_height == 18 ? 12 : 5)) { - if (h261_resync(h) < 0) - break; - h261_decode_gob(h); - } - ff_MPV_frame_end(s); - - av_assert0(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type); - av_assert0(s->current_picture.f.pict_type == s->pict_type); - - if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0) - return ret; - ff_print_debug_info(s, s->current_picture_ptr, pict); - - *got_frame = 1; - - return get_consumed_bytes(s, buf_size); -} - -static av_cold int h261_decode_end(AVCodecContext *avctx) -{ - H261Context *h = avctx->priv_data; - MpegEncContext *s = &h->s; - - ff_MPV_common_end(s); - return 0; -} - -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), - .init = h261_decode_init, - .close = h261_decode_end, - .decode = h261_decode_frame, - .capabilities = CODEC_CAP_DR1, - .max_lowres = 3, -}; |