Statistics
| Branch: | Revision:

ffmpeg / libavcodec / parser.c @ 2912e87a

History | View | Annotate | Download (10.9 KB)

1
/*
2
 * Audio and Video frame extraction
3
 * Copyright (c) 2003 Fabrice Bellard
4
 * Copyright (c) 2003 Michael Niedermayer
5
 *
6
 * This file is part of Libav.
7
 *
8
 * Libav is free software; you can redistribute it and/or
9
 * modify it under the terms of the GNU Lesser General Public
10
 * License as published by the Free Software Foundation; either
11
 * version 2.1 of the License, or (at your option) any later version.
12
 *
13
 * Libav is distributed in the hope that it will be useful,
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
19
 * License along with Libav; if not, write to the Free Software
20
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21
 */
22

    
23
#include "parser.h"
24

    
25
static AVCodecParser *av_first_parser = NULL;
26

    
27
AVCodecParser* av_parser_next(AVCodecParser *p){
28
    if(p) return p->next;
29
    else  return av_first_parser;
30
}
31

    
32
void av_register_codec_parser(AVCodecParser *parser)
33
{
34
    parser->next = av_first_parser;
35
    av_first_parser = parser;
36
}
37

    
38
AVCodecParserContext *av_parser_init(int codec_id)
39
{
40
    AVCodecParserContext *s;
41
    AVCodecParser *parser;
42
    int ret;
43

    
44
    if(codec_id == CODEC_ID_NONE)
45
        return NULL;
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 ||
50
            parser->codec_ids[2] == codec_id ||
51
            parser->codec_ids[3] == codec_id ||
52
            parser->codec_ids[4] == codec_id)
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
    }
74
    s->fetch_timestamp=1;
75
    s->pict_type = FF_I_TYPE;
76
    s->key_frame = -1;
77
    s->convergence_duration = 0;
78
    s->dts_sync_point       = INT_MIN;
79
    s->dts_ref_dts_delta    = INT_MIN;
80
    s->pts_dts_delta        = INT_MIN;
81
    return s;
82
}
83

    
84
void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){
85
    int i;
86

    
87
    s->dts= s->pts= AV_NOPTS_VALUE;
88
    s->pos= -1;
89
    s->offset= 0;
90
    for(i = 0; i < AV_PARSER_PTS_NB; i++) {
91
        if (   s->cur_offset + off >= s->cur_frame_offset[i]
92
            && (s->frame_offset < s->cur_frame_offset[i] ||
93
              (!s->frame_offset && !s->next_frame_offset)) // first field/frame
94
            //check is disabled  because mpeg-ts doesnt send complete PES packets
95
            && /*s->next_frame_offset + off <*/  s->cur_frame_end[i]){
96
            s->dts= s->cur_frame_dts[i];
97
            s->pts= s->cur_frame_pts[i];
98
            s->pos= s->cur_frame_pos[i];
99
            s->offset = s->next_frame_offset - s->cur_frame_offset[i];
100
            if(remove)
101
                s->cur_frame_offset[i]= INT64_MAX;
102
            if(s->cur_offset + off < s->cur_frame_end[i])
103
                break;
104
        }
105
    }
106
}
107

    
108
/**
109
 *
110
 * @param buf           input
111
 * @param buf_size      input length, to signal EOF, this should be 0 (so that the last frame can be output)
112
 * @param pts           input presentation timestamp
113
 * @param dts           input decoding timestamp
114
 * @param poutbuf       will contain a pointer to the first byte of the output frame
115
 * @param poutbuf_size  will contain the length of the output frame
116
 * @return the number of bytes of the input bitstream used
117
 *
118
 * Example:
119
 * @code
120
 *   while(in_len){
121
 *       len = av_parser_parse(myparser, AVCodecContext, &data, &size,
122
 *                                       in_data, in_len,
123
 *                                       pts, dts);
124
 *       in_data += len;
125
 *       in_len  -= len;
126
 *
127
 *       if(size)
128
 *          decode_frame(data, size);
129
 *   }
130
 * @endcode
131
 *
132
 * @deprecated Use av_parser_parse2() instead.
133
 */
134
int av_parser_parse(AVCodecParserContext *s,
135
                    AVCodecContext *avctx,
136
                    uint8_t **poutbuf, int *poutbuf_size,
137
                    const uint8_t *buf, int buf_size,
138
                    int64_t pts, int64_t dts)
139
{
140
    return av_parser_parse2(s, avctx, poutbuf, poutbuf_size, buf, buf_size, pts, dts, AV_NOPTS_VALUE);
141
}
142

    
143
int av_parser_parse2(AVCodecParserContext *s,
144
                     AVCodecContext *avctx,
145
                     uint8_t **poutbuf, int *poutbuf_size,
146
                     const uint8_t *buf, int buf_size,
147
                     int64_t pts, int64_t dts,
148
                     int64_t pos)
149
{
150
    int index, i;
151
    uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
152

    
153
    if(!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
154
        s->next_frame_offset =
155
        s->cur_offset        = pos;
156
        s->flags |= PARSER_FLAG_FETCHED_OFFSET;
157
    }
158

    
159
    if (buf_size == 0) {
160
        /* padding is always necessary even if EOF, so we add it here */
161
        memset(dummy_buf, 0, sizeof(dummy_buf));
162
        buf = dummy_buf;
163
    } else if (s->cur_offset + buf_size !=
164
               s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
165
        /* add a new packet descriptor */
166
            i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
167
            s->cur_frame_start_index = i;
168
            s->cur_frame_offset[i] = s->cur_offset;
169
            s->cur_frame_end[i] = s->cur_offset + buf_size;
170
            s->cur_frame_pts[i] = pts;
171
            s->cur_frame_dts[i] = dts;
172
            s->cur_frame_pos[i] = pos;
173
    }
174

    
175
    if (s->fetch_timestamp){
176
        s->fetch_timestamp=0;
177
        s->last_pts = s->pts;
178
        s->last_dts = s->dts;
179
        s->last_pos = s->pos;
180
        ff_fetch_timestamp(s, 0, 0);
181
    }
182

    
183
    /* WARNING: the returned index can be negative */
184
    index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
185
//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);
186
    /* update the file pointer */
187
    if (*poutbuf_size) {
188
        /* fill the data for the current frame */
189
        s->frame_offset = s->next_frame_offset;
190

    
191
        /* offset of the next frame */
192
        s->next_frame_offset = s->cur_offset + index;
193
        s->fetch_timestamp=1;
194
    }
195
    if (index < 0)
196
        index = 0;
197
    s->cur_offset += index;
198
    return index;
199
}
200

    
201
/**
202
 *
203
 * @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
204
 * @deprecated use AVBitstreamFilter
205
 */
206
int av_parser_change(AVCodecParserContext *s,
207
                     AVCodecContext *avctx,
208
                     uint8_t **poutbuf, int *poutbuf_size,
209
                     const uint8_t *buf, int buf_size, int keyframe){
210

    
211
    if(s && s->parser->split){
212
        if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
213
            int i= s->parser->split(avctx, buf, buf_size);
214
            buf += i;
215
            buf_size -= i;
216
        }
217
    }
218

    
219
    /* cast to avoid warning about discarding qualifiers */
220
    *poutbuf= (uint8_t *) buf;
221
    *poutbuf_size= buf_size;
222
    if(avctx->extradata){
223
        if(  (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
224
            /*||(s->pict_type != FF_I_TYPE && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
225
            /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
226
            int size= buf_size + avctx->extradata_size;
227
            *poutbuf_size= size;
228
            *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
229

    
230
            memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
231
            memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
232
            return 1;
233
        }
234
    }
235

    
236
    return 0;
237
}
238

    
239
void av_parser_close(AVCodecParserContext *s)
240
{
241
    if(s){
242
        if (s->parser->parser_close)
243
            s->parser->parser_close(s);
244
        av_free(s->priv_data);
245
        av_free(s);
246
    }
247
}
248

    
249
/*****************************************************/
250

    
251
/**
252
 * combines the (truncated) bitstream to a complete frame
253
 * @return -1 if no complete frame could be created, AVERROR(ENOMEM) if there was a memory allocation error
254
 */
255
int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
256
{
257
#if 0
258
    if(pc->overread){
259
        printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
260
        printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
261
    }
262
#endif
263

    
264
    /* Copy overread bytes from last frame into buffer. */
265
    for(; pc->overread>0; pc->overread--){
266
        pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
267
    }
268

    
269
    /* flush remaining if EOF */
270
    if(!*buf_size && next == END_NOT_FOUND){
271
        next= 0;
272
    }
273

    
274
    pc->last_index= pc->index;
275

    
276
    /* copy into buffer end return */
277
    if(next == END_NOT_FOUND){
278
        void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
279

    
280
        if(!new_buffer)
281
            return AVERROR(ENOMEM);
282
        pc->buffer = new_buffer;
283
        memcpy(&pc->buffer[pc->index], *buf, *buf_size);
284
        pc->index += *buf_size;
285
        return -1;
286
    }
287

    
288
    *buf_size=
289
    pc->overread_index= pc->index + next;
290

    
291
    /* append to buffer */
292
    if(pc->index){
293
        void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
294

    
295
        if(!new_buffer)
296
            return AVERROR(ENOMEM);
297
        pc->buffer = new_buffer;
298
        memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
299
        pc->index = 0;
300
        *buf= pc->buffer;
301
    }
302

    
303
    /* store overread bytes */
304
    for(;next < 0; next++){
305
        pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
306
        pc->state64 = (pc->state64<<8) | pc->buffer[pc->last_index + next];
307
        pc->overread++;
308
    }
309

    
310
#if 0
311
    if(pc->overread){
312
        printf("overread %d, state:%X next:%d index:%d o_index:%d\n", pc->overread, pc->state, next, pc->index, pc->overread_index);
313
        printf("%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
314
    }
315
#endif
316

    
317
    return 0;
318
}
319

    
320
void ff_parse_close(AVCodecParserContext *s)
321
{
322
    ParseContext *pc = s->priv_data;
323

    
324
    av_freep(&pc->buffer);
325
}
326

    
327
void ff_parse1_close(AVCodecParserContext *s)
328
{
329
    ParseContext1 *pc1 = s->priv_data;
330

    
331
    av_free(pc1->pc.buffer);
332
    av_free(pc1->enc);
333
}
334

    
335
/*************************/
336

    
337
int ff_mpeg4video_split(AVCodecContext *avctx,
338
                           const uint8_t *buf, int buf_size)
339
{
340
    int i;
341
    uint32_t state= -1;
342

    
343
    for(i=0; i<buf_size; i++){
344
        state= (state<<8) | buf[i];
345
        if(state == 0x1B3 || state == 0x1B6)
346
            return i-3;
347
    }
348
    return 0;
349
}