diff options
Diffstat (limited to 'ffmpeg1/libavcodec/dca_parser.c')
| -rw-r--r-- | ffmpeg1/libavcodec/dca_parser.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/dca_parser.c b/ffmpeg1/libavcodec/dca_parser.c new file mode 100644 index 0000000..266520f --- /dev/null +++ b/ffmpeg1/libavcodec/dca_parser.c @@ -0,0 +1,208 @@ +/* + * DCA parser + * Copyright (C) 2004 Gildas Bazin + * Copyright (C) 2004 Benjamin Zores + * Copyright (C) 2006 Benjamin Larsson + * Copyright (C) 2007 Konstantin Shishkov + * + * 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 + */ + +#include "parser.h" +#include "dca.h" +#include "dca_parser.h" +#include "get_bits.h" +#include "put_bits.h" + +typedef struct DCAParseContext { + ParseContext pc; + uint32_t lastmarker; + int size; + int framesize; + int hd_pos; +} DCAParseContext; + +#define IS_MARKER(state, i, buf, buf_size) \ + ((state == DCA_MARKER_14B_LE && (i < buf_size-2) && (buf[i+1] & 0xF0) == 0xF0 && buf[i+2] == 0x07) \ + || (state == DCA_MARKER_14B_BE && (i < buf_size-2) && buf[i+1] == 0x07 && (buf[i+2] & 0xF0) == 0xF0) \ + || state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE || state == DCA_HD_MARKER) + +/** + * Find the end of the current frame in the bitstream. + * @return the position of the first byte of the next frame, or -1 + */ +static int dca_find_frame_end(DCAParseContext * pc1, const uint8_t * buf, + int buf_size) +{ + int start_found, i; + uint32_t state; + ParseContext *pc = &pc1->pc; + + start_found = pc->frame_start_found; + state = pc->state; + + i = 0; + if (!start_found) { + for (i = 0; i < buf_size; i++) { + state = (state << 8) | buf[i]; + if (IS_MARKER(state, i, buf, buf_size)) { + if (!pc1->lastmarker || state == pc1->lastmarker || pc1->lastmarker == DCA_HD_MARKER) { + start_found = 1; + pc1->lastmarker = state; + break; + } + } + } + } + if (start_found) { + for (; i < buf_size; i++) { + pc1->size++; + state = (state << 8) | buf[i]; + if (state == DCA_HD_MARKER && !pc1->hd_pos) + pc1->hd_pos = pc1->size; + if (IS_MARKER(state, i, buf, buf_size) && (state == pc1->lastmarker || pc1->lastmarker == DCA_HD_MARKER)) { + if(pc1->framesize > pc1->size) + continue; + // We have to check that we really read a full frame here, and that it isn't a pure HD frame, because their size is not constant. + if(!pc1->framesize && state == pc1->lastmarker && state != DCA_HD_MARKER){ + pc1->framesize = pc1->hd_pos ? pc1->hd_pos : pc1->size; + } + pc->frame_start_found = 0; + pc->state = -1; + pc1->size = 0; + return i - 3; + } + } + } + pc->frame_start_found = start_found; + pc->state = state; + return END_NOT_FOUND; +} + +static av_cold int dca_parse_init(AVCodecParserContext * s) +{ + DCAParseContext *pc1 = s->priv_data; + + pc1->lastmarker = 0; + return 0; +} + +int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst, + int max_size) +{ + uint32_t mrk; + int i, tmp; + const uint16_t *ssrc = (const uint16_t *) src; + uint16_t *sdst = (uint16_t *) dst; + PutBitContext pb; + + if ((unsigned) src_size > (unsigned) max_size) + src_size = max_size; + + mrk = AV_RB32(src); + switch (mrk) { + case DCA_MARKER_RAW_BE: + memcpy(dst, src, src_size); + return src_size; + case DCA_MARKER_RAW_LE: + for (i = 0; i < (src_size + 1) >> 1; i++) + *sdst++ = av_bswap16(*ssrc++); + return src_size; + case DCA_MARKER_14B_BE: + case DCA_MARKER_14B_LE: + init_put_bits(&pb, dst, max_size); + for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) { + tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF; + put_bits(&pb, 14, tmp); + } + flush_put_bits(&pb); + return (put_bits_count(&pb) + 7) >> 3; + default: + return AVERROR_INVALIDDATA; + } +} + +static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration, + int *sample_rate) +{ + GetBitContext gb; + uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 }; + int ret, sample_blocks, sr_code; + + if (buf_size < 12) + return AVERROR_INVALIDDATA; + + if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0) + return ret; + + init_get_bits(&gb, hdr, 96); + + skip_bits_long(&gb, 39); + sample_blocks = get_bits(&gb, 7) + 1; + if (sample_blocks < 8) + return AVERROR_INVALIDDATA; + *duration = 256 * (sample_blocks / 8); + + skip_bits(&gb, 20); + sr_code = get_bits(&gb, 4); + *sample_rate = avpriv_dca_sample_rates[sr_code]; + if (*sample_rate == 0) + return AVERROR_INVALIDDATA; + + return 0; +} + +static int dca_parse(AVCodecParserContext * s, + AVCodecContext * avctx, + const uint8_t ** poutbuf, int *poutbuf_size, + const uint8_t * buf, int buf_size) +{ + DCAParseContext *pc1 = s->priv_data; + ParseContext *pc = &pc1->pc; + int next, duration, sample_rate; + + if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { + next = buf_size; + } else { + next = dca_find_frame_end(pc1, buf, buf_size); + + if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { + *poutbuf = NULL; + *poutbuf_size = 0; + return buf_size; + } + } + + /* read the duration and sample rate from the frame header */ + if (!dca_parse_params(buf, buf_size, &duration, &sample_rate)) { + s->duration = duration; + avctx->sample_rate = sample_rate; + } else + s->duration = 0; + + *poutbuf = buf; + *poutbuf_size = buf_size; + return next; +} + +AVCodecParser ff_dca_parser = { + .codec_ids = { AV_CODEC_ID_DTS }, + .priv_data_size = sizeof(DCAParseContext), + .parser_init = dca_parse_init, + .parser_parse = dca_parse, + .parser_close = ff_parse_close, +}; |