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https://github.com/FFmpeg/FFmpeg.git
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a969a914f5
The parser only parses the core, and thus has a duration relative to the core sample rate only, not the actual stream sample rate. FATE references changed due to now correct timestamps.
186 lines
5.8 KiB
C
186 lines
5.8 KiB
C
/*
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* DCA parser
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* Copyright (C) 2004 Gildas Bazin
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* Copyright (C) 2004 Benjamin Zores
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* Copyright (C) 2006 Benjamin Larsson
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* Copyright (C) 2007 Konstantin Shishkov
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "dca.h"
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#include "dca_syncwords.h"
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#include "get_bits.h"
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#include "parser.h"
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typedef struct DCAParseContext {
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ParseContext pc;
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uint32_t lastmarker;
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int size;
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int framesize;
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} DCAParseContext;
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#define IS_CORE_MARKER(state) \
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(((state & 0xFFFFFFFFF0FF) == (((uint64_t)DCA_SYNCWORD_CORE_14B_LE << 16) | 0xF007)) || \
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((state & 0xFFFFFFFFFFF0) == (((uint64_t)DCA_SYNCWORD_CORE_14B_BE << 16) | 0x07F0)) || \
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((state & 0xFFFFFFFF00FC) == (((uint64_t)DCA_SYNCWORD_CORE_LE << 16) | 0x00FC)) || \
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((state & 0xFFFFFFFFFC00) == (((uint64_t)DCA_SYNCWORD_CORE_BE << 16) | 0xFC00)))
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#define IS_EXSS_MARKER(state) ((state & 0xFFFFFFFF) == DCA_SYNCWORD_SUBSTREAM)
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#define IS_MARKER(state) (IS_CORE_MARKER(state) || IS_EXSS_MARKER(state))
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#define CORE_MARKER(state) ((state >> 16) & 0xFFFFFFFF)
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#define EXSS_MARKER(state) (state & 0xFFFFFFFF)
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/**
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* Find the end of the current frame in the bitstream.
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* @return the position of the first byte of the next frame, or -1
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*/
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static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf,
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int buf_size)
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{
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int start_found, i;
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uint64_t state;
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ParseContext *pc = &pc1->pc;
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start_found = pc->frame_start_found;
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state = pc->state64;
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i = 0;
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if (!start_found) {
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for (i = 0; i < buf_size; i++) {
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state = (state << 8) | buf[i];
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if (IS_MARKER(state)) {
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if (!pc1->lastmarker ||
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pc1->lastmarker == CORE_MARKER(state) ||
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pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM) {
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start_found = 1;
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if (IS_EXSS_MARKER(state))
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pc1->lastmarker = EXSS_MARKER(state);
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else
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pc1->lastmarker = CORE_MARKER(state);
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i++;
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break;
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}
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}
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}
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}
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if (start_found) {
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for (; i < buf_size; i++) {
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pc1->size++;
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state = (state << 8) | buf[i];
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if (IS_MARKER(state) &&
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(pc1->lastmarker == CORE_MARKER(state) ||
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pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {
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if (pc1->framesize > pc1->size)
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continue;
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pc->frame_start_found = 0;
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pc->state64 = -1;
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pc1->size = 0;
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return IS_EXSS_MARKER(state) ? i - 3 : i - 5;
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}
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}
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}
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pc->frame_start_found = start_found;
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pc->state64 = state;
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return END_NOT_FOUND;
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}
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static av_cold int dca_parse_init(AVCodecParserContext *s)
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{
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DCAParseContext *pc1 = s->priv_data;
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pc1->lastmarker = 0;
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return 0;
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}
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static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
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int *sample_rate, int *framesize)
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{
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GetBitContext gb;
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uint8_t hdr[12 + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
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int ret, sample_blocks, sr_code;
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if (buf_size < 12)
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return AVERROR_INVALIDDATA;
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if ((ret = avpriv_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
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return ret;
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init_get_bits(&gb, hdr, 96);
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skip_bits_long(&gb, 39);
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sample_blocks = get_bits(&gb, 7) + 1;
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if (sample_blocks < 8)
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return AVERROR_INVALIDDATA;
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*duration = 256 * (sample_blocks / 8);
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*framesize = get_bits(&gb, 14) + 1;
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if (*framesize < 95)
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return AVERROR_INVALIDDATA;
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skip_bits(&gb, 6);
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sr_code = get_bits(&gb, 4);
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*sample_rate = avpriv_dca_sample_rates[sr_code];
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if (*sample_rate == 0)
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return AVERROR_INVALIDDATA;
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return 0;
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}
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static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx,
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const uint8_t **poutbuf, int *poutbuf_size,
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const uint8_t *buf, int buf_size)
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{
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DCAParseContext *pc1 = s->priv_data;
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ParseContext *pc = &pc1->pc;
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int next, duration, sample_rate;
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if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
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next = buf_size;
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} else {
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next = dca_find_frame_end(pc1, buf, buf_size);
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if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
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*poutbuf = NULL;
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*poutbuf_size = 0;
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return buf_size;
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}
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}
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/* read the duration and sample rate from the frame header */
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if (!dca_parse_params(buf, buf_size, &duration, &sample_rate, &pc1->framesize)) {
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if (!avctx->sample_rate)
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avctx->sample_rate = sample_rate;
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s->duration = av_rescale(duration, avctx->sample_rate, sample_rate);
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} else
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s->duration = 0;
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*poutbuf = buf;
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*poutbuf_size = buf_size;
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return next;
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}
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AVCodecParser ff_dca_parser = {
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.codec_ids = { AV_CODEC_ID_DTS },
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.priv_data_size = sizeof(DCAParseContext),
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.parser_init = dca_parse_init,
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.parser_parse = dca_parse,
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.parser_close = ff_parse_close,
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};
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