unused variable
[libav.git] / libavcodec / parser.c
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1/*
2 * Audio and Video frame extraction
3 * Copyright (c) 2003 Fabrice Bellard.
4 * Copyright (c) 2003 Michael Niedermayer.
5 *
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6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
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9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
b78e7197 11 * version 2.1 of the License, or (at your option) any later version.
8424cf50 12 *
b78e7197 13 * FFmpeg is distributed in the hope that it will be useful,
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14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
b78e7197 19 * License along with FFmpeg; if not, write to the Free Software
5509bffa 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
8424cf50 21 */
1fddeecd 22
4067d81b 23#include "parser.h"
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24
25AVCodecParser *av_first_parser = NULL;
26
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27AVCodecParser* av_parser_next(AVCodecParser *p){
28 if(p) return p->next;
29 else return av_first_parser;
30}
31
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32void av_register_codec_parser(AVCodecParser *parser)
33{
34 parser->next = av_first_parser;
35 av_first_parser = parser;
36}
37
38AVCodecParserContext *av_parser_init(int codec_id)
39{
40 AVCodecParserContext *s;
41 AVCodecParser *parser;
42 int ret;
115329f1 43
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44 if(codec_id == CODEC_ID_NONE)
45 return NULL;
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46
47 for(parser = av_first_parser; parser != NULL; parser = parser->next) {
48 if (parser->codec_ids[0] == codec_id ||
49 parser->codec_ids[1] == codec_id ||
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50 parser->codec_ids[2] == codec_id ||
51 parser->codec_ids[3] == codec_id ||
52 parser->codec_ids[4] == codec_id)
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53 goto found;
54 }
55 return NULL;
56 found:
57 s = av_mallocz(sizeof(AVCodecParserContext));
58 if (!s)
59 return NULL;
60 s->parser = parser;
61 s->priv_data = av_mallocz(parser->priv_data_size);
62 if (!s->priv_data) {
63 av_free(s);
64 return NULL;
65 }
66 if (parser->parser_init) {
67 ret = parser->parser_init(s);
68 if (ret != 0) {
69 av_free(s->priv_data);
70 av_free(s);
71 return NULL;
72 }
73 }
a62aecce 74 s->fetch_timestamp=1;
adcb72b5 75 s->pict_type = FF_I_TYPE;
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76 return s;
77}
78
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79/**
80 *
81 * @param buf input
82 * @param buf_size input length, to signal EOF, this should be 0 (so that the last frame can be output)
83 * @param pts input presentation timestamp
84 * @param dts input decoding timestamp
85 * @param poutbuf will contain a pointer to the first byte of the output frame
86 * @param poutbuf_size will contain the length of the output frame
87 * @return the number of bytes of the input bitstream used
88 *
89 * Example:
90 * @code
91 * while(in_len){
92 * len = av_parser_parse(myparser, AVCodecContext, &data, &size,
93 * in_data, in_len,
94 * pts, dts);
95 * in_data += len;
96 * in_len -= len;
97 *
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98 * if(size)
99 * decode_frame(data, size);
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100 * }
101 * @endcode
102 */
115329f1 103int av_parser_parse(AVCodecParserContext *s,
8424cf50 104 AVCodecContext *avctx,
115329f1 105 uint8_t **poutbuf, int *poutbuf_size,
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106 const uint8_t *buf, int buf_size,
107 int64_t pts, int64_t dts)
8424cf50 108{
47917785 109 int index, i;
6e45e928 110 uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
115329f1 111
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112 if (buf_size == 0) {
113 /* padding is always necessary even if EOF, so we add it here */
114 memset(dummy_buf, 0, sizeof(dummy_buf));
115 buf = dummy_buf;
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116 } else {
117 /* add a new packet descriptor */
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118 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
119 s->cur_frame_start_index = i;
120 s->cur_frame_offset[i] = s->cur_offset;
121 s->cur_frame_end[i] = s->cur_offset + buf_size;
122 s->cur_frame_pts[i] = pts;
123 s->cur_frame_dts[i] = dts;
cb63a4b3 124 }
b84f2a35 125
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126 if (s->fetch_timestamp){
127 s->fetch_timestamp=0;
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128 s->last_pts = s->pts;
129 s->last_dts = s->dts;
130 s->dts= s->pts= AV_NOPTS_VALUE;
131 s->offset= 0;
132 for(i = 0; i < AV_PARSER_PTS_NB; i++) {
26f23725 133 if ( s->next_frame_offset >= s->cur_frame_offset[i]
cb63a4b3 134 &&(s-> frame_offset < s->cur_frame_offset[i] || !s->frame_offset)
26f23725 135 && s->next_frame_offset < s->cur_frame_end[i]){
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136 s->dts= s->cur_frame_dts[i];
137 s->pts= s->cur_frame_pts[i];
26f23725 138 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
cb63a4b3 139 }
b84f2a35 140 }
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141 }
142
8424cf50 143 /* WARNING: the returned index can be negative */
c53d2d90 144 index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
949b1a13 145//av_log(NULL, AV_LOG_DEBUG, "parser: in:%"PRId64", %"PRId64", out:%"PRId64", %"PRId64", in:%d out:%d id:%d\n", pts, dts, s->last_pts, s->last_dts, buf_size, *poutbuf_size, avctx->codec_id);
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146 /* update the file pointer */
147 if (*poutbuf_size) {
b84f2a35 148 /* fill the data for the current frame */
26f23725 149 s->frame_offset = s->next_frame_offset;
115329f1 150
b84f2a35 151 /* offset of the next frame */
26f23725 152 s->next_frame_offset = s->cur_offset + index;
591569b5 153 s->fetch_timestamp=1;
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154 }
155 if (index < 0)
156 index = 0;
157 s->cur_offset += index;
158 return index;
159}
160
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161/**
162 *
163 * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
748c2fca 164 * @deprecated use AVBitstreamFilter
73480a15 165 */
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166int av_parser_change(AVCodecParserContext *s,
167 AVCodecContext *avctx,
115329f1 168 uint8_t **poutbuf, int *poutbuf_size,
90ad92b3 169 const uint8_t *buf, int buf_size, int keyframe){
115329f1 170
90ad92b3 171 if(s && s->parser->split){
73480a15 172 if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
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173 int i= s->parser->split(avctx, buf, buf_size);
174 buf += i;
175 buf_size -= i;
176 }
177 }
178
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179 /* cast to avoid warning about discarding qualifiers */
180 *poutbuf= (uint8_t *) buf;
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181 *poutbuf_size= buf_size;
182 if(avctx->extradata){
183 if( (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
9701840b 184 /*||(s->pict_type != FF_I_TYPE && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
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185 /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
186 int size= buf_size + avctx->extradata_size;
187 *poutbuf_size= size;
188 *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
115329f1 189
90ad92b3 190 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
73480a15 191 memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
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192 return 1;
193 }
194 }
195
196 return 0;
197}
198
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199void av_parser_close(AVCodecParserContext *s)
200{
99c1c388 201 if(s){
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202 if (s->parser->parser_close)
203 s->parser->parser_close(s);
204 av_free(s->priv_data);
205 av_free(s);
99c1c388 206 }
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207}
208
209/*****************************************************/
210
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211/**
212 * combines the (truncated) bitstream to a complete frame
1f96bafb 213 * @returns -1 if no complete frame could be created, AVERROR(ENOMEM) if there was a memory allocation error
8424cf50 214 */
c53d2d90 215int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
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216{
217#if 0
218 if(pc->overread){
219 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
220 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
221 }
222#endif
223
e42dba48 224 /* Copy overread bytes from last frame into buffer. */
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225 for(; pc->overread>0; pc->overread--){
226 pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
227 }
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228
229 /* flush remaining if EOF */
230 if(!*buf_size && next == END_NOT_FOUND){
231 next= 0;
232 }
233
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234 pc->last_index= pc->index;
235
236 /* copy into buffer end return */
237 if(next == END_NOT_FOUND){
1f96bafb 238 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
8424cf50 239
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240 if(!new_buffer)
241 return AVERROR(ENOMEM);
242 pc->buffer = new_buffer;
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243 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
244 pc->index += *buf_size;
245 return -1;
246 }
247
248 *buf_size=
249 pc->overread_index= pc->index + next;
115329f1 250
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251 /* append to buffer */
252 if(pc->index){
1f96bafb 253 void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
8424cf50 254
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255 if(!new_buffer)
256 return AVERROR(ENOMEM);
257 pc->buffer = new_buffer;
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258 memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
259 pc->index = 0;
260 *buf= pc->buffer;
261 }
262
263 /* store overread bytes */
264 for(;next < 0; next++){
265 pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
266 pc->overread++;
267 }
268
269#if 0
270 if(pc->overread){
271 printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
272 printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
273 }
274#endif
275
276 return 0;
277}
278
e4cb187d 279void ff_parse_close(AVCodecParserContext *s)
8424cf50 280{
e4cb187d 281 ParseContext *pc = s->priv_data;
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282
283 av_free(pc->buffer);
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284}
285
4067d81b 286void ff_parse1_close(AVCodecParserContext *s)
8424cf50 287{
e4cb187d 288 ParseContext1 *pc1 = s->priv_data;
8424cf50 289
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290 av_free(pc1->pc.buffer);
291 av_free(pc1->enc);
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292}
293
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294/*************************/
295
d136d2fc 296int ff_mpeg4video_split(AVCodecContext *avctx,
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297 const uint8_t *buf, int buf_size)
298{
299 int i;
300 uint32_t state= -1;
115329f1 301
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302 for(i=0; i<buf_size; i++){
303 state= (state<<8) | buf[i];
304 if(state == 0x1B3 || state == 0x1B6)
73480a15 305 return i-3;
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306 }
307 return 0;
308}