?? flac.c.svn-base
字號:
decoded[i] += sum >> qlevel; } } return 0;}static inline int decode_subframe(FLACContext *s, int channel){ int type, wasted = 0; int i, tmp; s->curr_bps = s->bps; if(channel == 0){ if(s->decorrelation == RIGHT_SIDE) s->curr_bps++; }else{ if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE) s->curr_bps++; } if (get_bits1(&s->gb)) { av_log(s->avctx, AV_LOG_ERROR, "invalid subframe padding\n"); return -1; } type = get_bits(&s->gb, 6);// wasted = get_bits1(&s->gb);// if (wasted)// {// while (!get_bits1(&s->gb))// wasted++;// if (wasted)// wasted++;// s->curr_bps -= wasted;// }#if 0 wasted= 16 - av_log2(show_bits(&s->gb, 17)); skip_bits(&s->gb, wasted+1); s->curr_bps -= wasted;#else if (get_bits1(&s->gb)) { wasted = 1; while (!get_bits1(&s->gb)) wasted++; s->curr_bps -= wasted; av_log(s->avctx, AV_LOG_DEBUG, "%d wasted bits\n", wasted); }#endif//FIXME use av_log2 for types if (type == 0) { av_log(s->avctx, AV_LOG_DEBUG, "coding type: constant\n"); tmp = get_sbits(&s->gb, s->curr_bps); for (i = 0; i < s->blocksize; i++) s->decoded[channel][i] = tmp; } else if (type == 1) { av_log(s->avctx, AV_LOG_DEBUG, "coding type: verbatim\n"); for (i = 0; i < s->blocksize; i++) s->decoded[channel][i] = get_sbits(&s->gb, s->curr_bps); } else if ((type >= 8) && (type <= 12)) {// av_log(s->avctx, AV_LOG_DEBUG, "coding type: fixed\n"); if (decode_subframe_fixed(s, channel, type & ~0x8) < 0) return -1; } else if (type >= 32) {// av_log(s->avctx, AV_LOG_DEBUG, "coding type: lpc\n"); if (decode_subframe_lpc(s, channel, (type & ~0x20)+1) < 0) return -1; } else { av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n"); return -1; } if (wasted) { int i; for (i = 0; i < s->blocksize; i++) s->decoded[channel][i] <<= wasted; } return 0;}static int decode_frame(FLACContext *s, int alloc_data_size){ int blocksize_code, sample_rate_code, sample_size_code, assignment, i, crc8; int decorrelation, bps, blocksize, samplerate; blocksize_code = get_bits(&s->gb, 4); sample_rate_code = get_bits(&s->gb, 4); assignment = get_bits(&s->gb, 4); /* channel assignment */ if (assignment < 8 && s->channels == assignment+1) decorrelation = INDEPENDENT; else if (assignment >=8 && assignment < 11 && s->channels == 2) decorrelation = LEFT_SIDE + assignment - 8; else { av_log(s->avctx, AV_LOG_ERROR, "unsupported channel assignment %d (channels=%d)\n", assignment, s->channels); return -1; } sample_size_code = get_bits(&s->gb, 3); if(sample_size_code == 0) bps= s->bps; else if((sample_size_code != 3) && (sample_size_code != 7)) bps = sample_size_table[sample_size_code]; else { av_log(s->avctx, AV_LOG_ERROR, "invalid sample size code (%d)\n", sample_size_code); return -1; } if (get_bits1(&s->gb)) { av_log(s->avctx, AV_LOG_ERROR, "broken stream, invalid padding\n"); return -1; } if(get_utf8(&s->gb) < 0){ av_log(s->avctx, AV_LOG_ERROR, "utf8 fscked\n"); return -1; }#if 0 if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/ (s->min_blocksize != s->max_blocksize)){ }else{ }#endif if (blocksize_code == 0) blocksize = s->min_blocksize; else if (blocksize_code == 6) blocksize = get_bits(&s->gb, 8)+1; else if (blocksize_code == 7) blocksize = get_bits(&s->gb, 16)+1; else blocksize = blocksize_table[blocksize_code]; if(blocksize > s->max_blocksize){ av_log(s->avctx, AV_LOG_ERROR, "blocksize %d > %d\n", blocksize, s->max_blocksize); return -1; } if(blocksize * s->channels * sizeof(int16_t) > alloc_data_size) return -1; if (sample_rate_code == 0){ samplerate= s->samplerate; }else if ((sample_rate_code > 3) && (sample_rate_code < 12)) samplerate = sample_rate_table[sample_rate_code]; else if (sample_rate_code == 12) samplerate = get_bits(&s->gb, 8) * 1000; else if (sample_rate_code == 13) samplerate = get_bits(&s->gb, 16); else if (sample_rate_code == 14) samplerate = get_bits(&s->gb, 16) * 10; else{ av_log(s->avctx, AV_LOG_ERROR, "illegal sample rate code %d\n", sample_rate_code); return -1; } skip_bits(&s->gb, 8); crc8 = av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, s->gb.buffer, get_bits_count(&s->gb)/8); if(crc8){ av_log(s->avctx, AV_LOG_ERROR, "header crc mismatch crc=%2X\n", crc8); return -1; } s->blocksize = blocksize; s->samplerate = samplerate; s->bps = bps; s->decorrelation= decorrelation;// dump_headers(s); /* subframes */ for (i = 0; i < s->channels; i++) {// av_log(s->avctx, AV_LOG_DEBUG, "decoded: %x residual: %x\n", s->decoded[i], s->residual[i]); if (decode_subframe(s, i) < 0) return -1; } align_get_bits(&s->gb); /* frame footer */ skip_bits(&s->gb, 16); /* data crc */ return 0;}static int flac_decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size){ FLACContext *s = avctx->priv_data; int tmp = 0, i, j = 0, input_buf_size = 0; int16_t *samples = data; int alloc_data_size= *data_size; *data_size=0; if(s->max_framesize == 0){ s->max_framesize= 65536; // should hopefully be enough for the first header s->bitstream= av_fast_realloc(s->bitstream, &s->allocated_bitstream_size, s->max_framesize); } if(1 && s->max_framesize){//FIXME truncated buf_size= FFMAX(FFMIN(buf_size, s->max_framesize - s->bitstream_size), 0); input_buf_size= buf_size; if(s->bitstream_index + s->bitstream_size + buf_size > s->allocated_bitstream_size){// printf("memmove\n"); memmove(s->bitstream, &s->bitstream[s->bitstream_index], s->bitstream_size); s->bitstream_index=0; } memcpy(&s->bitstream[s->bitstream_index + s->bitstream_size], buf, buf_size); buf= &s->bitstream[s->bitstream_index]; buf_size += s->bitstream_size; s->bitstream_size= buf_size; if(buf_size < s->max_framesize){// printf("wanna more data ...\n"); return input_buf_size; } } init_get_bits(&s->gb, buf, buf_size*8); if (!metadata_parse(s)) { tmp = show_bits(&s->gb, 16); if((tmp & 0xFFFE) != 0xFFF8){ av_log(s->avctx, AV_LOG_ERROR, "FRAME HEADER not here\n"); while(get_bits_count(&s->gb)/8+2 < buf_size && (show_bits(&s->gb, 16) & 0xFFFE) != 0xFFF8) skip_bits(&s->gb, 8); goto end; // we may not have enough bits left to decode a frame, so try next time } skip_bits(&s->gb, 16); if (decode_frame(s, alloc_data_size) < 0){ av_log(s->avctx, AV_LOG_ERROR, "decode_frame() failed\n"); s->bitstream_size=0; s->bitstream_index=0; return -1; } }#if 0 /* fix the channel order here */ if (s->order == MID_SIDE) { short *left = samples; short *right = samples + s->blocksize; for (i = 0; i < s->blocksize; i += 2) { uint32_t x = s->decoded[0][i]; uint32_t y = s->decoded[0][i+1]; right[i] = x - (y / 2); left[i] = right[i] + y; } *data_size = 2 * s->blocksize; } else { for (i = 0; i < s->channels; i++) { switch(s->order) { case INDEPENDENT: for (j = 0; j < s->blocksize; j++) samples[(s->blocksize*i)+j] = s->decoded[i][j]; break; case LEFT_SIDE: case RIGHT_SIDE: if (i == 0) for (j = 0; j < s->blocksize; j++) samples[(s->blocksize*i)+j] = s->decoded[0][j]; else for (j = 0; j < s->blocksize; j++) samples[(s->blocksize*i)+j] = s->decoded[0][j] - s->decoded[i][j]; break;// case MID_SIDE:// av_log(s->avctx, AV_LOG_DEBUG, "mid-side unsupported\n"); } *data_size += s->blocksize; } }#else#define DECORRELATE(left, right)\ assert(s->channels == 2);\ for (i = 0; i < s->blocksize; i++)\ {\ int a= s->decoded[0][i];\ int b= s->decoded[1][i];\ *samples++ = ((left) << (24 - s->bps)) >> 8;\ *samples++ = ((right) << (24 - s->bps)) >> 8;\ }\ break; switch(s->decorrelation) { case INDEPENDENT: for (j = 0; j < s->blocksize; j++) { for (i = 0; i < s->channels; i++) *samples++ = (s->decoded[i][j] << (24 - s->bps)) >> 8; } break; case LEFT_SIDE: DECORRELATE(a,a-b) case RIGHT_SIDE: DECORRELATE(a+b,b) case MID_SIDE: DECORRELATE( (a-=b>>1) + b, a) }#endif *data_size = (int8_t *)samples - (int8_t *)data;// av_log(s->avctx, AV_LOG_DEBUG, "data size: %d\n", *data_size);// s->last_blocksize = s->blocksize;end: i= (get_bits_count(&s->gb)+7)/8;; if(i > buf_size){ av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", i - buf_size); s->bitstream_size=0; s->bitstream_index=0; return -1; } if(s->bitstream_size){ s->bitstream_index += i; s->bitstream_size -= i; return input_buf_size; }else return i;}static int flac_decode_close(AVCodecContext *avctx){ FLACContext *s = avctx->priv_data; int i; for (i = 0; i < s->channels; i++) { av_freep(&s->decoded[i]); } av_freep(&s->bitstream); return 0;}static void flac_flush(AVCodecContext *avctx){ FLACContext *s = avctx->priv_data; s->bitstream_size= s->bitstream_index= 0;}AVCodec flac_decoder = { "flac", CODEC_TYPE_AUDIO, CODEC_ID_FLAC, sizeof(FLACContext), flac_decode_init, NULL, flac_decode_close, flac_decode_frame, .flush= flac_flush,};
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -