3 * Copyright (C) 2004 Gildas Bazin
4 * Copyright (C) 2004 Benjamin Zores
5 * Copyright (C) 2006 Benjamin Larsson
6 * Copyright (C) 2007 Konstantin Shishkov
8 * This file is part of FFmpeg.
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #include "dca_parser.h"
31 typedef struct DCAParseContext {
39 #define IS_MARKER(state, i, buf, buf_size) \
40 ((state == DCA_MARKER_14B_LE && (i < buf_size-2) && (buf[i+1] & 0xF0) == 0xF0 && buf[i+2] == 0x07) \
41 || (state == DCA_MARKER_14B_BE && (i < buf_size-2) && buf[i+1] == 0x07 && (buf[i+2] & 0xF0) == 0xF0) \
42 || state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE || state == DCA_HD_MARKER)
45 * Find the end of the current frame in the bitstream.
46 * @return the position of the first byte of the next frame, or -1
48 static int dca_find_frame_end(DCAParseContext * pc1, const uint8_t * buf,
53 ParseContext *pc = &pc1->pc;
55 start_found = pc->frame_start_found;
60 for (i = 0; i < buf_size; i++) {
61 state = (state << 8) | buf[i];
62 if (IS_MARKER(state, i, buf, buf_size)) {
63 if (!pc1->lastmarker || state == pc1->lastmarker || pc1->lastmarker == DCA_HD_MARKER) {
65 pc1->lastmarker = state;
72 for (; i < buf_size; i++) {
74 state = (state << 8) | buf[i];
75 if (state == DCA_HD_MARKER && !pc1->hd_pos)
76 pc1->hd_pos = pc1->size;
77 if (IS_MARKER(state, i, buf, buf_size) && (state == pc1->lastmarker || pc1->lastmarker == DCA_HD_MARKER)) {
78 if(pc1->framesize > pc1->size)
80 // 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.
81 if(!pc1->framesize && state == pc1->lastmarker && state != DCA_HD_MARKER){
82 pc1->framesize = pc1->hd_pos ? pc1->hd_pos : pc1->size;
84 pc->frame_start_found = 0;
91 pc->frame_start_found = start_found;
96 static av_cold int dca_parse_init(AVCodecParserContext * s)
98 DCAParseContext *pc1 = s->priv_data;
104 int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
109 const uint16_t *ssrc = (const uint16_t *) src;
110 uint16_t *sdst = (uint16_t *) dst;
113 if ((unsigned) src_size > (unsigned) max_size)
118 case DCA_MARKER_RAW_BE:
119 memcpy(dst, src, src_size);
121 case DCA_MARKER_RAW_LE:
122 for (i = 0; i < (src_size + 1) >> 1; i++)
123 *sdst++ = av_bswap16(*ssrc++);
125 case DCA_MARKER_14B_BE:
126 case DCA_MARKER_14B_LE:
127 init_put_bits(&pb, dst, max_size);
128 for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
129 tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
130 put_bits(&pb, 14, tmp);
133 return (put_bits_count(&pb) + 7) >> 3;
135 return AVERROR_INVALIDDATA;
139 static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
143 uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
144 int ret, sample_blocks, sr_code;
147 return AVERROR_INVALIDDATA;
149 if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
152 init_get_bits(&gb, hdr, 96);
154 skip_bits_long(&gb, 39);
155 sample_blocks = get_bits(&gb, 7) + 1;
156 if (sample_blocks < 8)
157 return AVERROR_INVALIDDATA;
158 *duration = 256 * (sample_blocks / 8);
161 sr_code = get_bits(&gb, 4);
162 *sample_rate = avpriv_dca_sample_rates[sr_code];
163 if (*sample_rate == 0)
164 return AVERROR_INVALIDDATA;
169 static int dca_parse(AVCodecParserContext * s,
170 AVCodecContext * avctx,
171 const uint8_t ** poutbuf, int *poutbuf_size,
172 const uint8_t * buf, int buf_size)
174 DCAParseContext *pc1 = s->priv_data;
175 ParseContext *pc = &pc1->pc;
176 int next, duration, sample_rate;
178 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
181 next = dca_find_frame_end(pc1, buf, buf_size);
183 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
190 /* read the duration and sample rate from the frame header */
191 if (!dca_parse_params(buf, buf_size, &duration, &sample_rate)) {
192 s->duration = duration;
193 avctx->sample_rate = sample_rate;
198 *poutbuf_size = buf_size;
202 AVCodecParser ff_dca_parser = {
203 .codec_ids = { AV_CODEC_ID_DTS },
204 .priv_data_size = sizeof(DCAParseContext),
205 .parser_init = dca_parse_init,
206 .parser_parse = dca_parse,
207 .parser_close = ff_parse_close,