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author | Fabrice Bellard <fabrice@bellard.org> | 2002-10-03 21:07:39 +0000 |
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committer | Fabrice Bellard <fabrice@bellard.org> | 2002-10-03 21:07:39 +0000 |
commit | 5d2231ee8fed0db4a520b646e2b5149c245bc0a4 (patch) | |
tree | 0744ce39950957b58a52b4ff97cc68ccc8292b93 /libavcodec/dv.c | |
parent | 652f01978626257e38d1e333af45055d2b9465b5 (diff) | |
download | ffmpeg-streaming-5d2231ee8fed0db4a520b646e2b5149c245bc0a4.zip ffmpeg-streaming-5d2231ee8fed0db4a520b646e2b5149c245bc0a4.tar.gz |
first working version of DV video decoder
Originally committed as revision 998 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec/dv.c')
-rw-r--r-- | libavcodec/dv.c | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/libavcodec/dv.c b/libavcodec/dv.c new file mode 100644 index 0000000..0077474 --- /dev/null +++ b/libavcodec/dv.c @@ -0,0 +1,632 @@ +/* + * DV decoder + * Copyright (c) 2002 Fabrice Bellard. + * + * This library 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 of the License, or (at your option) any later version. + * + * This library 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 this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include "avcodec.h" +#include "dsputil.h" +#include "mpegvideo.h" +#include "simple_idct.h" + +#define NTSC_FRAME_SIZE 120000 +#define PAL_FRAME_SIZE 144000 + +#define TEX_VLC_BITS 9 + +typedef struct DVVideoDecodeContext { + AVCodecContext *avctx; + GetBitContext gb; + VLC *vlc; + int sampling_411; /* 0 = 420, 1 = 411 */ + int width, height; + UINT8 *current_picture[3]; /* picture structure */ + int linesize[3]; + DCTELEM block[5*6][64] __align8; + UINT8 dv_zigzag[2][64]; + /* XXX: move it to static storage ? */ + UINT8 dv_shift[2][2][22][64]; + void (*idct_put[2])(UINT8 *dest, int line_size, DCTELEM *block); +} DVVideoDecodeContext; + +#include "dvdata.h" + +static VLC dv_vlc; +/* XXX: also include quantization */ +static RL_VLC_ELEM *dv_rl_vlc[1]; + +static void dv_build_unquantize_tables(DVVideoDecodeContext *s) +{ + int i, e, q; + + /* NOTE: max left shift is 6 */ + for(e = 0; e < 2; e++) { + for(q = 0; q < 22; q++) { + /* 88 unquant */ + for(i = 1; i < 64; i++) { + /* 88 table */ + s->dv_shift[0][e][q][i] = + dv_quant_shifts[q][dv_88_areas[i]] + e + 1; + } + + /* 248 unquant */ + for(i = 1; i < 64; i++) { + /* 248 table */ + s->dv_shift[1][e][q][i] = + dv_quant_shifts[q][dv_248_areas[i]] + e + 1; + } + } + } +} + +static int dvvideo_decode_init(AVCodecContext *avctx) +{ + DVVideoDecodeContext *s = avctx->priv_data; + static int done; + + if (!done) { + int i; + + done = 1; + + /* NOTE: as a trick, we use the fact the no codes are unused + to accelerate the parsing of partial codes */ + init_vlc(&dv_vlc, TEX_VLC_BITS, NB_DV_VLC, + dv_vlc_len, 1, 1, dv_vlc_bits, 2, 2); + + dv_rl_vlc[0] = av_malloc(dv_vlc.table_size * sizeof(RL_VLC_ELEM)); + for(i = 0; i < dv_vlc.table_size; i++){ + int code= dv_vlc.table[i][0]; + int len = dv_vlc.table[i][1]; + int level, run; + + if(len<0){ //more bits needed + run= 0; + level= code; + } else if (code == (NB_DV_VLC - 1)) { + /* EOB */ + run = 0; + level = 256; + } else { + run= dv_vlc_run[code] + 1; + level= dv_vlc_level[code]; + } + dv_rl_vlc[0][i].len = len; + dv_rl_vlc[0][i].level = level; + dv_rl_vlc[0][i].run = run; + } + } + /* XXX: do it only for constant case */ + dv_build_unquantize_tables(s); + { + /* XXX: fix that : use mmx when possible */ + s->idct_put[0] = simple_idct_put; + s->idct_put[1] = simple_idct248_put; + + memcpy(s->dv_zigzag[0], ff_zigzag_direct, 64); + memcpy(s->dv_zigzag[1], dv_248_zigzag, 64); + } + return 0; +} + +//#define VLC_DEBUG + +typedef struct MBInfo { + const UINT8 *shift_table[6]; + const UINT8 *scan_table[6]; + UINT8 pos[6]; /* position in block */ + UINT8 eob_reached[6]; /* true if EOB has been reached */ + UINT8 dct_mode[6]; + UINT8 partial_bit_count[6]; + UINT16 partial_bit_buffer[6]; + UINT8 bit_buffer[80 + 4]; /* allow some slack */ + int bits_left; +} MBInfo; + +/* block size in bits */ +const static UINT16 block_sizes[6] = { + 112, 112, 112, 112, 80, 80 +}; + +#ifndef ALT_BITSTREAM_READER +#error only works with ALT_BITSTREAM_READER +#endif + +/* decode ac coefs */ +static void dv_decode_ac(DVVideoDecodeContext *s, + MBInfo *mb, INT16 *block, int j, int last_index) +{ + int last_re_index; + const UINT8 *scan_table = mb->scan_table[j]; + const UINT8 *shift_table = mb->shift_table[j]; + int pos = mb->pos[j]; + int level, pos1, sign, run; + int partial_bit_count; + + OPEN_READER(re, &s->gb); + +#ifdef VLC_DEBUG + printf("start %d\n", j); +#endif + + /* if we must parse a partial vlc, we do it here */ + partial_bit_count = mb->partial_bit_count[j]; + if (partial_bit_count > 0) { + UINT8 buf[4]; + UINT32 v; + int l, l1; + GetBitContext gb1; + + /* build the dummy bit buffer */ + l = 16 - partial_bit_count; + UPDATE_CACHE(re, &s->gb); +#ifdef VLC_DEBUG + printf("show=%04x\n", SHOW_UBITS(re, &s->gb, 16)); +#endif + v = (mb->partial_bit_buffer[j] << l) | SHOW_UBITS(re, &s->gb, l); + buf[0] = v >> 8; + buf[1] = v; +#ifdef VLC_DEBUG + printf("v=%04x cnt=%d %04x\n", + v, partial_bit_count, (mb->partial_bit_buffer[j] << l)); +#endif + /* try to read the codeword */ + init_get_bits(&gb1, buf, 4); + { + OPEN_READER(re1, &gb1); + UPDATE_CACHE(re1, &gb1); + GET_RL_VLC(level, run, re1, &gb1, dv_rl_vlc[0], + TEX_VLC_BITS, 2); + l = re1_index; + CLOSE_READER(re1, &gb1); + } +#ifdef VLC_DEBUG + printf("****run=%d level=%d size=%d\n", run, level, l); +#endif + /* compute codeword length */ + l1 = (level != 256 && level != 0); + /* if too long, we cannot parse */ + l -= partial_bit_count; + if ((re_index + l + l1) > last_index) + return; + /* skip read bits */ + last_re_index = 0; /* avoid warning */ + re_index += l; + /* by redefinition, if we can read the vlc, all partial bits + will be read (otherwise we could have read the vlc before) */ + mb->partial_bit_count[j] = 0; + UPDATE_CACHE(re, &s->gb); + goto handle_vlc; + } + + /* get the AC coefficients until last_index is reached */ + for(;;) { + UPDATE_CACHE(re, &s->gb); +#ifdef VLC_DEBUG + printf("%2d: bits=%04x index=%d\n", + pos, SHOW_UBITS(re, &s->gb, 16), re_index); +#endif + last_re_index = re_index; + GET_RL_VLC(level, run, re, &s->gb, dv_rl_vlc[0], + TEX_VLC_BITS, 2); + handle_vlc: +#ifdef VLC_DEBUG + printf("run=%d level=%d\n", run, level); +#endif + if (level == 256) { + if (re_index > last_index) { + cannot_read: + /* put position before read code */ + re_index = last_re_index; + mb->eob_reached[j] = 0; + break; + } + /* EOB */ + mb->eob_reached[j] = 1; + break; + } else if (level != 0) { + if ((re_index + 1) > last_index) + goto cannot_read; + sign = SHOW_SBITS(re, &s->gb, 1); + level = (level ^ sign) - sign; + LAST_SKIP_BITS(re, &s->gb, 1); + pos += run; + /* error */ + if (pos >= 64) { + goto read_error; + } + pos1 = scan_table[pos]; + level = level << shift_table[pos1]; + block[pos1] = level; + // printf("run=%d level=%d shift=%d\n", run, level, shift_table[pos1]); + } else { + if (re_index > last_index) + goto cannot_read; + /* level is zero: means run without coding. No + sign is coded */ + pos += run; + /* error */ + if (pos >= 64) { + read_error: +#if defined(VLC_DEBUG) || 1 + printf("error pos=%d\n", pos); +#endif + /* for errors, we consider the eob is reached */ + mb->eob_reached[j] = 1; + break; + } + } + } + CLOSE_READER(re, &s->gb); + mb->pos[j] = pos; +} + +static inline void bit_copy(PutBitContext *pb, GetBitContext *gb, int bits_left) +{ + while (bits_left >= 16) { + put_bits(pb, 16, get_bits(gb, 16)); + bits_left -= 16; + } + if (bits_left > 0) { + put_bits(pb, bits_left, get_bits(gb, bits_left)); + } +} + +/* mb_x and mb_y are in units of 8 pixels */ +static inline void dv_decode_video_segment(DVVideoDecodeContext *s, + UINT8 *buf_ptr1, + const UINT16 *mb_pos_ptr) +{ + int quant, dc, dct_mode, class1, j; + int mb_index, mb_x, mb_y, v, last_index; + DCTELEM *block, *block1; + int c_offset, bits_left; + UINT8 *y_ptr; + MBInfo mb_data[5], *mb; + void (*idct_put)(UINT8 *dest, int line_size, DCTELEM *block); + UINT8 *buf_ptr; + PutBitContext pb, vs_pb; + UINT8 vs_bit_buffer[5 * 80 + 4]; + int vs_bit_count; + + memset(s->block, 0, sizeof(s->block)); + + /* pass 1 : read DC and AC coefficients in blocks */ + buf_ptr = buf_ptr1; + block1 = &s->block[0][0]; + mb = mb_data; + init_put_bits(&vs_pb, vs_bit_buffer, 5 * 80, NULL, NULL); + vs_bit_count = 0; + for(mb_index = 0; mb_index < 5; mb_index++) { + /* skip header */ + quant = buf_ptr[3] & 0x0f; + buf_ptr += 4; + init_put_bits(&pb, mb->bit_buffer, 80, NULL, NULL); + mb->bits_left = 0; + block = block1; + for(j = 0;j < 6; j++) { + /* NOTE: size is not important here */ + init_get_bits(&s->gb, buf_ptr, 14); + + /* get the dc */ + dc = get_bits(&s->gb, 9); + dc = (dc << (32 - 9)) >> (32 - 9); + dct_mode = get_bits1(&s->gb); + mb->dct_mode[j] = dct_mode; + mb->scan_table[j] = s->dv_zigzag[dct_mode]; + class1 = get_bits(&s->gb, 2); + mb->shift_table[j] = s->dv_shift[dct_mode][class1 == 3] + [quant + dv_quant_offset[class1]]; + dc = dc << 2; + /* convert to unsigned because 128 is not added in the + standard IDCT */ + dc += 1024; + block[0] = dc; + last_index = block_sizes[j]; + buf_ptr += last_index >> 3; + mb->pos[j] = 0; + mb->partial_bit_count[j] = 0; + + dv_decode_ac(s, mb, block, j, last_index); + + /* write the remaining bits in a new buffer only if the + block is finished */ + bits_left = last_index - s->gb.index; + if (mb->eob_reached[j]) { + mb->partial_bit_count[j] = 0; + mb->bits_left += bits_left; + bit_copy(&pb, &s->gb, bits_left); + } else { + /* should be < 16 bits otherwise a codeword could have + been parsed */ + mb->partial_bit_count[j] = bits_left; + mb->partial_bit_buffer[j] = get_bits(&s->gb, bits_left); + } + block += 64; + } + + flush_put_bits(&pb); + + /* pass 2 : we can do it just after */ +#ifdef VLC_DEBUG + printf("***pass 2 size=%d\n", mb->bits_left); +#endif + block = block1; + init_get_bits(&s->gb, mb->bit_buffer, 80); + for(j = 0;j < 6; j++) { + if (!mb->eob_reached[j] && s->gb.index < mb->bits_left) { + dv_decode_ac(s, mb, block, j, mb->bits_left); + /* if still not finished, no need to parse other blocks */ + if (!mb->eob_reached[j]) { + /* we could not parse the current AC coefficient, + so we add the remaining bytes */ + bits_left = mb->bits_left - s->gb.index; + if (bits_left > 0) { + mb->partial_bit_count[j] += bits_left; + mb->partial_bit_buffer[j] = + (mb->partial_bit_buffer[j] << bits_left) | + get_bits(&s->gb, bits_left); + } + goto next_mb; + } + } + block += 64; + } + /* all blocks are finished, so the extra bytes can be used at + the video segment level */ + bits_left = mb->bits_left - s->gb.index; + vs_bit_count += bits_left; + bit_copy(&vs_pb, &s->gb, bits_left); + next_mb: + mb++; + block1 += 6 * 64; + } + + /* we need a pass other the whole video segment */ + flush_put_bits(&vs_pb); + +#ifdef VLC_DEBUG + printf("***pass 3 size=%d\n", vs_bit_count); +#endif + block = &s->block[0][0]; + mb = mb_data; + init_get_bits(&s->gb, vs_bit_buffer, 5 * 80); + for(mb_index = 0; mb_index < 5; mb_index++) { + for(j = 0;j < 6; j++) { + if (!mb->eob_reached[j]) { +#ifdef VLC_DEBUG + printf("start %d:%d\n", mb_index, j); +#endif + dv_decode_ac(s, mb, block, j, vs_bit_count); + } + block += 64; + } + mb++; + } + + /* compute idct and place blocks */ + block = &s->block[0][0]; + mb = mb_data; + for(mb_index = 0; mb_index < 5; mb_index++) { + v = *mb_pos_ptr++; + mb_x = v & 0xff; + mb_y = v >> 8; + y_ptr = s->current_picture[0] + (mb_y * s->linesize[0] * 8) + (mb_x * 8); + if (s->sampling_411) + c_offset = (mb_y * s->linesize[1] * 8) + ((mb_x >> 2) * 8); + else + c_offset = ((mb_y >> 1) * s->linesize[1] * 8) + ((mb_x >> 1) * 8); + for(j = 0;j < 6; j++) { + idct_put = s->idct_put[mb->dct_mode[j]]; + if (j < 4) { + if (s->sampling_411) { + idct_put(y_ptr + (j * 8), s->linesize[0], block); + } else { + idct_put(y_ptr + ((j & 1) * 8) + ((j >> 1) * 8 * s->linesize[0]), + s->linesize[0], block); + } + } else { + /* don't ask me why they inverted Cb and Cr ! */ + idct_put(s->current_picture[6 - j] + c_offset, + s->linesize[6 - j], block); + } + block += 64; + } + mb++; + } +} + + +/* NOTE: exactly one frame must be given (120000 bytes for NTSC, + 144000 bytes for PAL) */ +static int dvvideo_decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + UINT8 *buf, int buf_size) +{ + DVVideoDecodeContext *s = avctx->priv_data; + int sct, dsf, apt, ds, nb_dif_segs, vs, size, width, height, i; + UINT8 *buf_ptr; + const UINT16 *mb_pos_ptr; + AVPicture *picture; + + /* parse id */ + init_get_bits(&s->gb, buf, buf_size); + sct = get_bits(&s->gb, 3); + if (sct != 0) + return -1; + skip_bits(&s->gb, 5); + get_bits(&s->gb, 4); /* dsn (sequence number */ + get_bits(&s->gb, 1); /* fsc (channel number) */ + skip_bits(&s->gb, 3); + get_bits(&s->gb, 8); /* dbn (diff block number 0-134) */ + + dsf = get_bits(&s->gb, 1); /* 0 = NTSC 1 = PAL */ + if (get_bits(&s->gb, 1) != 0) + return -1; + skip_bits(&s->gb, 11); + apt = get_bits(&s->gb, 3); /* apt */ + + get_bits(&s->gb, 1); /* tf1 */ + skip_bits(&s->gb, 4); + get_bits(&s->gb, 3); /* ap1 */ + + get_bits(&s->gb, 1); /* tf2 */ + skip_bits(&s->gb, 4); + get_bits(&s->gb, 3); /* ap2 */ + + get_bits(&s->gb, 1); /* tf3 */ + skip_bits(&s->gb, 4); + get_bits(&s->gb, 3); /* ap3 */ + + /* init size */ + width = 720; + if (dsf) { + if (buf_size != PAL_FRAME_SIZE) + return -1; + height = 576; + nb_dif_segs = 12; + } else { + if (buf_size != NTSC_FRAME_SIZE) + return -1; + height = 480; + nb_dif_segs = 10; + } + + /* (re)alloc picture if needed */ + if (s->width != width || s->height != height) { + for(i=0;i<3;i++) + av_freep(&s->current_picture[i]); + for(i=0;i<3;i++) { + size = width * height; + s->linesize[i] = width; + if (i >= 1) { + size >>= 2; + s->linesize[i] >>= 1; + } + s->current_picture[i] = av_malloc(size); + if (!s->current_picture[i]) + return -1; + } + s->width = width; + s->height = height; + } + + /* XXX: is it correct to assume that 420 is always used in PAL + mode ? */ + s->sampling_411 = !dsf; + if (s->sampling_411) + mb_pos_ptr = dv_place_411; + else + mb_pos_ptr = dv_place_420; + + /* for each DIF segment */ + buf_ptr = buf; + for (ds = 0; ds < nb_dif_segs; ds++) { + buf_ptr += 6 * 80; /* skip DIF segment header */ + + for(vs = 0; vs < 27; vs++) { + if ((vs % 3) == 0) { + /* skip audio block */ + buf_ptr += 80; + } + dv_decode_video_segment(s, buf_ptr, mb_pos_ptr); + buf_ptr += 5 * 80; + mb_pos_ptr += 5; + } + } + + /* return image */ + avctx->width = width; + avctx->height = height; + if (s->sampling_411) + avctx->pix_fmt = PIX_FMT_YUV420P; /* XXX: incorrect, add PIX_FMT_YUV411P */ + else + avctx->pix_fmt = PIX_FMT_YUV420P; + if (dsf) + avctx->frame_rate = 25 * FRAME_RATE_BASE; + else + avctx->frame_rate = 30 * FRAME_RATE_BASE; + *data_size = sizeof(AVPicture); + picture = data; + for(i=0;i<3;i++) { + picture->data[i] = s->current_picture[i]; + picture->linesize[i] = s->linesize[i]; + } + return buf_size; +} + +static int dvvideo_decode_end(AVCodecContext *avctx) +{ + DVVideoDecodeContext *s = avctx->priv_data; + int i; + + for(i=0;i<3;i++) + av_freep(&s->current_picture[i]); + return 0; +} + +AVCodec dvvideo_decoder = { + "dvvideo", + CODEC_TYPE_VIDEO, + CODEC_ID_DVVIDEO, + sizeof(DVVideoDecodeContext), + dvvideo_decode_init, + NULL, + dvvideo_decode_end, + dvvideo_decode_frame, + 0, + NULL +}; + +typedef struct DVAudioDecodeContext { + AVCodecContext *avctx; + GetBitContext gb; + +} DVAudioDecodeContext; + +static int dvaudio_decode_init(AVCodecContext *avctx) +{ + // DVAudioDecodeContext *s = avctx->priv_data; + return 0; +} + +/* NOTE: exactly one frame must be given (120000 bytes for NTSC, + 144000 bytes for PAL) */ +static int dvaudio_decode_frame(AVCodecContext *avctx, + void *data, int *data_size, + UINT8 *buf, int buf_size) +{ + // DVAudioDecodeContext *s = avctx->priv_data; + return buf_size; +} + +static int dvaudio_decode_end(AVCodecContext *avctx) +{ + // DVAudioDecodeContext *s = avctx->priv_data; + return 0; +} + +AVCodec dvaudio_decoder = { + "dvaudio", + CODEC_TYPE_AUDIO, + CODEC_ID_DVAUDIO, + sizeof(DVAudioDecodeContext), + dvaudio_decode_init, + NULL, + dvaudio_decode_end, + dvaudio_decode_frame, + 0, + NULL +}; |