libavcodec/parser.c

   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/mem.h"
  29
  30 #include "parser.h"
  31
  32 AVCodecParserContext *av_parser_init(int codec_id)
  33 {
  34     AVCodecParserContext *s = NULL;
  35     const AVCodecParser *parser;
  36     void *i = 0;
  37     int ret;
  38
  39     if (codec_id == AV_CODEC_ID_NONE)
  40         return NULL;
  41
  42     while ((parser = av_parser_iterate(&i))) {
  43         if (parser->codec_ids[0] == codec_id ||
  44             parser->codec_ids[1] == codec_id ||
  45             parser->codec_ids[2] == codec_id ||
  46             parser->codec_ids[3] == codec_id ||
  47             parser->codec_ids[4] == codec_id ||
  48             parser->codec_ids[5] == codec_id ||
  49             parser->codec_ids[6] == 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 = 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     s->dts_sync_point       = INT_MIN;
  71     s->dts_ref_dts_delta    = INT_MIN;
  72     s->pts_dts_delta        = INT_MIN;
  73     s->format               = -1;
  74
  75     return s;
  76
  77 err_out:
  78     if (s)
  79         av_freep(&s->priv_data);
  80     av_free(s);
  81     return NULL;
  82 }
  83
  84 void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove, int fuzzy)
  85 {
  86     int i;
  87
  88     if (!fuzzy) {
  89         s->dts    =
  90         s->pts    = AV_NOPTS_VALUE;
  91         s->pos    = -1;
  92         s->offset = 0;
  93     }
  94     for (i = 0; i < AV_PARSER_PTS_NB; i++) {
  95         if (s->cur_offset + off >= s->cur_frame_offset[i] &&
  96             (s->frame_offset < s->cur_frame_offset[i] ||
  97              (!s->frame_offset && !s->next_frame_offset)) && // first field/frame
  98             // check disabled since MPEG-TS does not send complete PES packets
  99             /*s->next_frame_offset + off <*/  s->cur_frame_end[i]){
 100
 101             if (!fuzzy || s->cur_frame_dts[i] != AV_NOPTS_VALUE) {
 102                 s->dts    = s->cur_frame_dts[i];
 103                 s->pts    = s->cur_frame_pts[i];
 104                 s->pos    = s->cur_frame_pos[i];
 105                 s->offset = s->next_frame_offset - s->cur_frame_offset[i];
 106             }
 107             if (remove)
 108                 s->cur_frame_offset[i] = INT64_MAX;
 109             if (s->cur_offset + off < s->cur_frame_end[i])
 110                 break;
 111         }
 112     }
 113 }
 114
 115 int av_parser_parse2(AVCodecParserContext *s, AVCodecContext *avctx,
 116                      uint8_t **poutbuf, int *poutbuf_size,
 117                      const uint8_t *buf, int buf_size,
 118                      int64_t pts, int64_t dts, int64_t pos)
 119 {
 120     int index, i;
 121     uint8_t dummy_buf[AV_INPUT_BUFFER_PADDING_SIZE];
 122
 123     av_assert1(avctx->codec_id != AV_CODEC_ID_NONE);
 124
 125     /* Parsers only work for the specified codec ids. */
 126     av_assert1(avctx->codec_id == s->parser->codec_ids[0] ||
 127                avctx->codec_id == s->parser->codec_ids[1] ||
 128                avctx->codec_id == s->parser->codec_ids[2] ||
 129                avctx->codec_id == s->parser->codec_ids[3] ||
 130                avctx->codec_id == s->parser->codec_ids[4] ||
 131                avctx->codec_id == s->parser->codec_ids[5] ||
 132                avctx->codec_id == s->parser->codec_ids[6]);
 133
 134     if (!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
 135         s->next_frame_offset =
 136         s->cur_offset        = pos;
 137         s->flags            |= PARSER_FLAG_FETCHED_OFFSET;
 138     }
 139
 140     if (buf_size == 0) {
 141         /* padding is always necessary even if EOF, so we add it here */
 142         memset(dummy_buf, 0, sizeof(dummy_buf));
 143         buf = dummy_buf;
 144     } else if (s->cur_offset + buf_size != s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
 145         /* add a new packet descriptor */
 146         i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
 147         s->cur_frame_start_index = i;
 148         s->cur_frame_offset[i]   = s->cur_offset;
 149         s->cur_frame_end[i]      = s->cur_offset + buf_size;
 150         s->cur_frame_pts[i]      = pts;
 151         s->cur_frame_dts[i]      = dts;
 152         s->cur_frame_pos[i]      = pos;
 153     }
 154
 155     if (s->fetch_timestamp) {
 156         s->fetch_timestamp = 0;
 157         s->last_pts        = s->pts;
 158         s->last_dts        = s->dts;
 159         s->last_pos        = s->pos;
 160         ff_fetch_timestamp(s, 0, 0, 0);
 161     }
 162     /* WARNING: the returned index can be negative */
 163     index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
 164                                     poutbuf_size, buf, buf_size);
 165     av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
 166 #define FILL(name) if(s->name > 0 && avctx->name <= 0) avctx->name = s->name
 167     if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
 168         FILL(field_order);
 169         FILL(coded_width);
 170         FILL(coded_height);
 171         FILL(width);
 172         FILL(height);
 173     }
 174
 175     /* update the file pointer */
 176     if (*poutbuf_size) {
 177         /* fill the data for the current frame */
 178         s->frame_offset = s->next_frame_offset;
 179
 180         /* offset of the next frame */
 181         s->next_frame_offset = s->cur_offset + index;
 182         s->fetch_timestamp   = 1;
 183     } else {
 184         /* Don't return a pointer to dummy_buf. */
 185         *poutbuf = NULL;
 186     }
 187     if (index < 0)
 188         index = 0;
 189     s->cur_offset += index;
 190     return index;
 191 }
 192
 193 void av_parser_close(AVCodecParserContext *s)
 194 {
 195     if (s) {
 196         if (s->parser->parser_close)
 197             s->parser->parser_close(s);
 198         av_freep(&s->priv_data);
 199         av_free(s);
 200     }
 201 }
 202
 203 int ff_combine_frame(ParseContext *pc, int next,
 204                      const uint8_t **buf, int *buf_size)
 205 {
 206     if (pc->overread) {
 207         ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
 208                 pc->overread, pc->state, next, pc->index, pc->overread_index);
 209         ff_dlog(NULL, "%X %X %X %X\n",
 210                 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
 211     }
 212
 213     /* Copy overread bytes from last frame into buffer. */
 214     for (; pc->overread > 0; pc->overread--)
 215         pc->buffer[pc->index++] = pc->buffer[pc->overread_index++];
 216
 217     if (next > *buf_size)
 218         return AVERROR(EINVAL);
 219
 220     /* flush remaining if EOF */
 221     if (!*buf_size && next == END_NOT_FOUND)
 222         next = 0;
 223
 224     pc->last_index = pc->index;
 225
 226     /* copy into buffer end return */
 227     if (next == END_NOT_FOUND) {
 228         void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
 229                                            *buf_size + pc->index +
 230                                            AV_INPUT_BUFFER_PADDING_SIZE);
 231
 232         if (!new_buffer) {
 233             av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", *buf_size + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
 234             pc->index = 0;
 235             return AVERROR(ENOMEM);
 236         }
 237         pc->buffer = new_buffer;
 238         memcpy(&pc->buffer[pc->index], *buf, *buf_size);
 239         memset(&pc->buffer[pc->index + *buf_size], 0, AV_INPUT_BUFFER_PADDING_SIZE);
 240         pc->index += *buf_size;
 241         return -1;
 242     }
 243
 244     av_assert0(next >= 0 || pc->buffer);
 245
 246     *buf_size          =
 247     pc->overread_index = pc->index + next;
 248
 249     /* append to buffer */
 250     if (pc->index) {
 251         void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size,
 252                                            next + pc->index +
 253                                            AV_INPUT_BUFFER_PADDING_SIZE);
 254         if (!new_buffer) {
 255             av_log(NULL, AV_LOG_ERROR, "Failed to reallocate parser buffer to %d\n", next + pc->index + AV_INPUT_BUFFER_PADDING_SIZE);
 256             *buf_size =
 257             pc->overread_index =
 258             pc->index = 0;
 259             return AVERROR(ENOMEM);
 260         }
 261         pc->buffer = new_buffer;
 262         if (next > -AV_INPUT_BUFFER_PADDING_SIZE)
 263             memcpy(&pc->buffer[pc->index], *buf,
 264                    next + AV_INPUT_BUFFER_PADDING_SIZE);
 265         pc->index = 0;
 266         *buf      = pc->buffer;
 267     }
 268
 269     if (next < -8) {
 270         pc->overread += -8 - next;
 271         next = -8;
 272     }
 273     /* store overread bytes */
 274     for (; next < 0; next++) {
 275         pc->state   = pc->state   << 8 | pc->buffer[pc->last_index + next];
 276         pc->state64 = pc->state64 << 8 | pc->buffer[pc->last_index + next];
 277         pc->overread++;
 278     }
 279
 280     if (pc->overread) {
 281         ff_dlog(NULL, "overread %d, state:%"PRIX32" next:%d index:%d o_index:%d\n",
 282                 pc->overread, pc->state, next, pc->index, pc->overread_index);
 283         ff_dlog(NULL, "%X %X %X %X\n",
 284                 (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
 285     }
 286
 287     return 0;
 288 }
 289
 290 void ff_parse_close(AVCodecParserContext *s)
 291 {
 292     ParseContext *pc = s->priv_data;
 293
 294     av_freep(&pc->buffer);
 295 }