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 FFmpeg.
7 *
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include <inttypes.h>
24 #include <stdint.h>
25 #include <string.h>
26
27 #include "libavutil/avassert.h"
28 #include "libavutil/internal.h"
29 #include "libavutil/mem.h"
30
31 #include "internal.h"
32 #include "parser.h"
33
av_parser_init(int codec_id)34 AVCodecParserContext *av_parser_init(int codec_id)
35 {
36 AVCodecParserContext *s = NULL;
37 const AVCodecParser *parser;
38 void *i = 0;
39 int ret;
40
41 if (codec_id == AV_CODEC_ID_NONE)
42 return NULL;
43
44 while ((parser = av_parser_iterate(&i))) {
45 if (parser->codec_ids[0] == codec_id ||
46 parser->codec_ids[1] == codec_id ||
47 parser->codec_ids[2] == codec_id ||
48 parser->codec_ids[3] == codec_id ||
49 parser->codec_ids[4] == codec_id)
50 goto found;
51 }
52 return NULL;
53
54 found:
55 s = av_mallocz(sizeof(AVCodecParserContext));
56 if (!s)
57 goto err_out;
58 s->parser = (AVCodecParser*)parser;
59 s->priv_data = av_mallocz(parser->priv_data_size);
60 if (!s->priv_data)
61 goto err_out;
62 s->fetch_timestamp=1;
63 s->pict_type = AV_PICTURE_TYPE_I;
64 if (parser->parser_init) {
65 ret = parser->parser_init(s);
66 if (ret != 0)
67 goto err_out;
68 }
69 s->key_frame = -1;
70 #if FF_API_CONVERGENCE_DURATION
71 FF_DISABLE_DEPRECATION_WARNINGS
72 s->convergence_duration = 0;
73 FF_ENABLE_DEPRECATION_WARNINGS
74 #endif
75 s->dts_sync_point = INT_MIN;
76 s->dts_ref_dts_delta = INT_MIN;
77 s->pts_dts_delta = INT_MIN;
78 s->format = -1;
79
80 return s;
81
82 err_out:
83 if (s)
84 av_freep(&s->priv_data);
85 av_free(s);
86 return NULL;
87 }
88
ff_fetch_timestamp(AVCodecParserContext * s,int off,int remove,int fuzzy)89 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
90 {
91 int i;
92
93 if (!fuzzy) {
94 s->dts =
95 s->pts = AV_NOPTS_VALUE;
96 s->pos = -1;
97 s->offset = 0;
98 }
99 for (i = 0; i < AV_PARSER_PTS_NB; i++) {
100 if (s->cur_offset + off >= s->cur_frame_offset[i] &&
101 (s->frame_offset < s->cur_frame_offset[i] ||
102 (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
103 // check disabled since MPEG-TS does not send complete PES packets
104 /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
105
106 if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
107 s->dts = s->cur_frame_dts[i];
108 s->pts = s->cur_frame_pts[i];
109 s->pos = s->cur_frame_pos[i];
110 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
111 }
112 if (remove)
113 s->cur_frame_offset[i] = INT64_MAX;
114 if (s->cur_offset + off < s->cur_frame_end[i])
115 break;
116 }
117 }
118 }
119
av_parser_parse2(AVCodecParserContext * s,AVCodecContext * avctx,uint8_t ** poutbuf,int * poutbuf_size,const uint8_t * buf,int buf_size,int64_t pts,int64_t dts,int64_t pos)120 int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
121 uint8_t **poutbuf, int *poutbuf_size,
122 const uint8_t *buf, int buf_size,
123 int64_t pts, int64_t dts, int64_t pos)
124 {
125 int index, i;
126 uint8_t dummy_buf[AV_INPUT_BUFFER_PADDING_SIZE];
127
128 av_assert1(avctx->codec_id != AV_CODEC_ID_NONE);
129
130 /* Parsers only work for the specified codec ids. */
131 av_assert1(avctx->codec_id == s->parser->codec_ids[0] ||
132 avctx->codec_id == s->parser->codec_ids[1] ||
133 avctx->codec_id == s->parser->codec_ids[2] ||
134 avctx->codec_id == s->parser->codec_ids[3] ||
135 avctx->codec_id == s->parser->codec_ids[4]);
136
137 if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
138 s->next_frame_offset =
139 s->cur_offset = pos;
140 s->flags |= PARSER_FLAG_FETCHED_OFFSET;
141 }
142
143 if (buf_size == 0) {
144 /* padding is always necessary even if EOF, so we add it here */
145 memset(dummy_buf, 0, sizeof(dummy_buf));
146 buf = dummy_buf;
147 } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
148 /* add a new packet descriptor */
149 i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
150 s->cur_frame_start_index = i;
151 s->cur_frame_offset[i] = s->cur_offset;
152 s->cur_frame_end[i] = s->cur_offset + buf_size;
153 s->cur_frame_pts[i] = pts;
154 s->cur_frame_dts[i] = dts;
155 s->cur_frame_pos[i] = pos;
156 }
157
158 if (s->fetch_timestamp) {
159 s->fetch_timestamp = 0;
160 s->last_pts = s->pts;
161 s->last_dts = s->dts;
162 s->last_pos = s->pos;
163 ff_fetch_timestamp(s, 0, 0, 0);
164 }
165 /* WARNING: the returned index can be negative */
166 index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
167 poutbuf_size, buf, buf_size);
168 av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
169 #define FILL(name) if(s->name > 0 && avctx->name <= 0) avctx->name = s->name
170 if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
171 FILL(field_order);
172 }
173
174 /* update the file pointer */
175 if (*poutbuf_size) {
176 /* fill the data for the current frame */
177 s->frame_offset = s->next_frame_offset;
178
179 /* offset of the next frame */
180 s->next_frame_offset = s->cur_offset + index;
181 s->fetch_timestamp = 1;
182 }
183 if (index < 0)
184 index = 0;
185 s->cur_offset += index;
186 return index;
187 }
188
av_parser_change(AVCodecParserContext * s,AVCodecContext * avctx,uint8_t ** poutbuf,int * poutbuf_size,const uint8_t * buf,int buf_size,int keyframe)189 int av_parser_change(AVCodecParserContext *s, AVCodecContext *avctx,
190 uint8_t **poutbuf, int *poutbuf_size,
191 const uint8_t *buf, int buf_size, int keyframe)
192 {
193 if (s && s->parser->split) {
194 if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER ||
195 avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER) {
196 int i = s->parser->split(avctx, buf, buf_size);
197 buf += i;
198 buf_size -= i;
199 }
200 }
201
202 /* cast to avoid warning about discarding qualifiers */
203 *poutbuf = (uint8_t *) buf;
204 *poutbuf_size = buf_size;
205 if (avctx->extradata) {
206 if (keyframe && (avctx->flags2 & AV_CODEC_FLAG2_LOCAL_HEADER)) {
207 int size = buf_size + avctx->extradata_size;
208
209 *poutbuf_size = size;
210 *poutbuf = av_malloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
211 if (!*poutbuf)
212 return AVERROR(ENOMEM);
213
214 memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
215 memcpy(*poutbuf + avctx->extradata_size, buf,
216 buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
217 return 1;
218 }
219 }
220
221 return 0;
222 }
223
av_parser_close(AVCodecParserContext * s)224 void av_parser_close(AVCodecParserContext *s)
225 {
226 if (s) {
227 if (s->parser->parser_close)
228 s->parser->parser_close(s);
229 av_freep(&s->priv_data);
230 av_free(s);
231 }
232 }
233
ff_combine_frame(ParseContext * pc,int next,const uint8_t ** buf,int * buf_size)234 int ff_combine_frame(ParseContext *pc, int next,
235 const uint8_t **buf, int *buf_size)
236 {
237 if (pc->overread) {
238 ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
239 pc->overread, pc->state, next, pc->index, pc->overread_index);
240 ff_dlog(NULL, "%X %X %X %X\n",
241 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
242 }
243
244 /* Copy overread bytes from last frame into buffer. */
245 for (; pc->overread > 0; pc->overread--)
246 pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
247
248 if (next > *buf_size)
249 return AVERROR(EINVAL);
250
251 /* flush remaining if EOF */
252 if (!*buf_size && next == END_NOT_FOUND)
253 next = 0;
254
255 pc->last_index = pc->index;
256
257 /* copy into buffer end return */
258 if (next == END_NOT_FOUND) {
259 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
260 *buf_size + pc->index +
261 AV_INPUT_BUFFER_PADDING_SIZE);
262
263 if (!new_buffer) {
264 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
265 pc->index = 0;
266 return AVERROR(ENOMEM);
267 }
268 pc->buffer = new_buffer;
269 memcpy(&pc->buffer[pc->index], *buf, *buf_size);
270 pc->index += *buf_size;
271 return -1;
272 }
273
274 av_assert0(next >= 0 || pc->buffer);
275
276 *buf_size =
277 pc->overread_index = pc->index + next;
278
279 /* append to buffer */
280 if (pc->index) {
281 void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
282 next + pc->index +
283 AV_INPUT_BUFFER_PADDING_SIZE);
284 if (!new_buffer) {
285 av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
286 pc->overread_index =
287 pc->index = 0;
288 return AVERROR(ENOMEM);
289 }
290 pc->buffer = new_buffer;
291 if (next > -AV_INPUT_BUFFER_PADDING_SIZE)
292 memcpy(&pc->buffer[pc->index], *buf,
293 next + AV_INPUT_BUFFER_PADDING_SIZE);
294 pc->index = 0;
295 *buf = pc->buffer;
296 }
297
298 if (next < -8) {
299 pc->overread += -8 - next;
300 next = -8;
301 }
302 /* store overread bytes */
303 for (; next < 0; next++) {
304 pc->state = pc->state << 8 | pc->buffer[pc->last_index + next];
305 pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
306 pc->overread++;
307 }
308
309 if (pc->overread) {
310 ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
311 pc->overread, pc->state, next, pc->index, pc->overread_index);
312 ff_dlog(NULL, "%X %X %X %X\n",
313 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
314 }
315
316 return 0;
317 }
318
ff_parse_close(AVCodecParserContext * s)319 void ff_parse_close(AVCodecParserContext *s)
320 {
321 ParseContext *pc = s->priv_data;
322
323 av_freep(&pc->buffer);
324 }
325
ff_mpeg4video_split(AVCodecContext * avctx,const uint8_t * buf,int buf_size)326 int ff_mpeg4video_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
327 {
328 uint32_t state = -1;
329 const uint8_t *ptr = buf, *end = buf + buf_size;
330
331 while (ptr < end) {
332 ptr = avpriv_find_start_code(ptr, end, &state);
333 if (state == 0x1B3 || state == 0x1B6)
334 return ptr - 4 - buf;
335 }
336
337 return 0;
338 }
339