| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * Dirac parser | ||
| 3 | * | ||
| 4 | * Copyright (c) 2007-2008 Marco Gerards <marco@gnu.org> | ||
| 5 | * Copyright (c) 2008 BBC, Anuradha Suraparaju <asuraparaju@gmail.com> | ||
| 6 | * | ||
| 7 | * This file is part of FFmpeg. | ||
| 8 | * | ||
| 9 | * FFmpeg is free software; you can redistribute it and/or | ||
| 10 | * modify it under the terms of the GNU Lesser General Public | ||
| 11 | * License as published by the Free Software Foundation; either | ||
| 12 | * version 2.1 of the License, or (at your option) any later version. | ||
| 13 | * | ||
| 14 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 17 | * Lesser General Public License for more details. | ||
| 18 | * | ||
| 19 | * You should have received a copy of the GNU Lesser General Public | ||
| 20 | * License along with FFmpeg; if not, write to the Free Software | ||
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 22 | */ | ||
| 23 | |||
| 24 | /** | ||
| 25 | * @file | ||
| 26 | * Dirac Parser | ||
| 27 | * @author Marco Gerards <marco@gnu.org> | ||
| 28 | */ | ||
| 29 | |||
| 30 | #include <string.h> | ||
| 31 | |||
| 32 | #include "libavutil/attributes.h" | ||
| 33 | #include "libavutil/intreadwrite.h" | ||
| 34 | #include "libavutil/mem.h" | ||
| 35 | |||
| 36 | #include "avcodec.h" | ||
| 37 | |||
| 38 | #define DIRAC_PARSE_INFO_PREFIX 0x42424344 | ||
| 39 | |||
| 40 | /** | ||
| 41 | * Find the end of the current frame in the bitstream. | ||
| 42 | * @return the position of the first byte of the next frame or -1 | ||
| 43 | */ | ||
| 44 | typedef struct DiracParseContext { | ||
| 45 | int state; | ||
| 46 | int is_synced; | ||
| 47 | int sync_offset; | ||
| 48 | int header_bytes_needed; | ||
| 49 | int overread_index; | ||
| 50 | int buffer_size; | ||
| 51 | int index; | ||
| 52 | uint8_t *buffer; | ||
| 53 | int dirac_unit_size; | ||
| 54 | uint8_t *dirac_unit; | ||
| 55 | } DiracParseContext; | ||
| 56 | |||
| 57 | 812 | static int find_frame_end(DiracParseContext *pc, | |
| 58 | const uint8_t *buf, int buf_size) | ||
| 59 | { | ||
| 60 | 812 | uint32_t state = pc->state; | |
| 61 | 812 | int i = 0; | |
| 62 | |||
| 63 |
2/2✓ Branch 0 taken 2 times.
✓ Branch 1 taken 810 times.
|
812 | if (!pc->is_synced) { |
| 64 |
1/2✓ Branch 0 taken 8 times.
✗ Branch 1 not taken.
|
8 | for (i = 0; i < buf_size; i++) { |
| 65 | 8 | state = (state << 8) | buf[i]; | |
| 66 |
2/2✓ Branch 0 taken 2 times.
✓ Branch 1 taken 6 times.
|
8 | if (state == DIRAC_PARSE_INFO_PREFIX) { |
| 67 | 2 | state = -1; | |
| 68 | 2 | pc->is_synced = 1; | |
| 69 | 2 | pc->header_bytes_needed = 9; | |
| 70 | 2 | pc->sync_offset = i; | |
| 71 | 2 | break; | |
| 72 | } | ||
| 73 | } | ||
| 74 | } | ||
| 75 | |||
| 76 |
1/2✓ Branch 0 taken 812 times.
✗ Branch 1 not taken.
|
812 | if (pc->is_synced) { |
| 77 | 812 | pc->sync_offset = 0; | |
| 78 |
2/2✓ Branch 0 taken 669478 times.
✓ Branch 1 taken 656 times.
|
670134 | for (; i < buf_size; i++) { |
| 79 |
2/2✓ Branch 0 taken 156 times.
✓ Branch 1 taken 669322 times.
|
669478 | if (state == DIRAC_PARSE_INFO_PREFIX) { |
| 80 |
2/2✓ Branch 0 taken 154 times.
✓ Branch 1 taken 2 times.
|
156 | if ((buf_size - i) >= pc->header_bytes_needed) { |
| 81 | 154 | pc->state = -1; | |
| 82 | 154 | return i + pc->header_bytes_needed; | |
| 83 | } else { | ||
| 84 | 2 | pc->header_bytes_needed = 9 - (buf_size - i); | |
| 85 | 2 | break; | |
| 86 | } | ||
| 87 | } else | ||
| 88 | 669322 | state = (state << 8) | buf[i]; | |
| 89 | } | ||
| 90 | } | ||
| 91 | 658 | pc->state = state; | |
| 92 | 658 | return -1; | |
| 93 | } | ||
| 94 | |||
| 95 | typedef struct DiracParseUnit { | ||
| 96 | int next_pu_offset; | ||
| 97 | int prev_pu_offset; | ||
| 98 | uint8_t pu_type; | ||
| 99 | } DiracParseUnit; | ||
| 100 | |||
| 101 | 308 | static int unpack_parse_unit(DiracParseUnit *pu, DiracParseContext *pc, | |
| 102 | int offset) | ||
| 103 | { | ||
| 104 | int i; | ||
| 105 | int8_t *start; | ||
| 106 | static const uint8_t valid_pu_types[] = { | ||
| 107 | 0x00, 0x10, 0x20, 0x30, 0x08, 0x48, 0xC8, 0xE8, 0x0A, 0x0C, 0x0D, 0x0E, | ||
| 108 | 0x4C, 0x09, 0xCC, 0x88, 0xCB | ||
| 109 | }; | ||
| 110 | |||
| 111 |
2/4✓ Branch 0 taken 308 times.
✗ Branch 1 not taken.
✗ Branch 2 not taken.
✓ Branch 3 taken 308 times.
|
308 | if (offset < 0 || pc->index - 13 < offset) |
| 112 | ✗ | return 0; | |
| 113 | |||
| 114 | 308 | start = pc->buffer + offset; | |
| 115 | 308 | pu->pu_type = start[4]; | |
| 116 | |||
| 117 | 308 | pu->next_pu_offset = AV_RB32(start + 5); | |
| 118 | 308 | pu->prev_pu_offset = AV_RB32(start + 9); | |
| 119 | |||
| 120 | /* Check for valid parse code */ | ||
| 121 |
1/2✓ Branch 0 taken 1990 times.
✗ Branch 1 not taken.
|
1990 | for (i = 0; i < 17; i++) |
| 122 |
2/2✓ Branch 0 taken 308 times.
✓ Branch 1 taken 1682 times.
|
1990 | if (valid_pu_types[i] == pu->pu_type) |
| 123 | 308 | break; | |
| 124 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 308 times.
|
308 | if (i == 17) |
| 125 | ✗ | return 0; | |
| 126 | |||
| 127 |
3/4✓ Branch 0 taken 2 times.
✓ Branch 1 taken 306 times.
✓ Branch 2 taken 2 times.
✗ Branch 3 not taken.
|
308 | if (pu->pu_type == 0x10 && pu->next_pu_offset == 0x00) |
| 128 | 2 | pu->next_pu_offset = 13; /* The length of a parse info header */ | |
| 129 | |||
| 130 | /* Check if the parse offsets are somewhat sane */ | ||
| 131 |
2/4✓ Branch 0 taken 308 times.
✗ Branch 1 not taken.
✓ Branch 2 taken 308 times.
✗ Branch 3 not taken.
|
308 | if ((pu->next_pu_offset && pu->next_pu_offset < 13) || |
| 132 |
3/4✓ Branch 0 taken 306 times.
✓ Branch 1 taken 2 times.
✗ Branch 2 not taken.
✓ Branch 3 taken 306 times.
|
308 | (pu->prev_pu_offset && pu->prev_pu_offset < 13)) |
| 133 | ✗ | return 0; | |
| 134 | |||
| 135 | 308 | return 1; | |
| 136 | } | ||
| 137 | |||
| 138 | 812 | static int dirac_combine_frame(AVCodecParserContext *s, AVCodecContext *avctx, | |
| 139 | int next, const uint8_t **buf, int *buf_size) | ||
| 140 | { | ||
| 141 |
1/2✓ Branch 0 taken 812 times.
✗ Branch 1 not taken.
|
1624 | int parse_timing_info = (s->pts == AV_NOPTS_VALUE && |
| 142 |
1/2✓ Branch 0 taken 812 times.
✗ Branch 1 not taken.
|
812 | s->dts == AV_NOPTS_VALUE); |
| 143 | 812 | DiracParseContext *pc = s->priv_data; | |
| 144 | |||
| 145 |
2/2✓ Branch 0 taken 60 times.
✓ Branch 1 taken 752 times.
|
812 | if (pc->overread_index) { |
| 146 | 60 | memmove(pc->buffer, pc->buffer + pc->overread_index, | |
| 147 | 60 | pc->index - pc->overread_index); | |
| 148 | 60 | pc->index -= pc->overread_index; | |
| 149 | 60 | pc->overread_index = 0; | |
| 150 |
3/4✓ Branch 0 taken 2 times.
✓ Branch 1 taken 58 times.
✓ Branch 2 taken 2 times.
✗ Branch 3 not taken.
|
60 | if (*buf_size == 0 && pc->buffer[4] == 0x10) { |
| 151 | 2 | *buf = pc->buffer; | |
| 152 | 2 | *buf_size = pc->index; | |
| 153 | 2 | return 0; | |
| 154 | } | ||
| 155 | } | ||
| 156 | |||
| 157 |
2/2✓ Branch 0 taken 656 times.
✓ Branch 1 taken 154 times.
|
810 | if (next == -1) { |
| 158 | /* Found a possible frame start but not a frame end */ | ||
| 159 | void *new_buffer = | ||
| 160 | 656 | av_fast_realloc(pc->buffer, &pc->buffer_size, | |
| 161 | 656 | pc->index + (*buf_size - pc->sync_offset)); | |
| 162 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 656 times.
|
656 | if (!new_buffer) |
| 163 | ✗ | return AVERROR(ENOMEM); | |
| 164 | 656 | pc->buffer = new_buffer; | |
| 165 | 656 | memcpy(pc->buffer + pc->index, (*buf + pc->sync_offset), | |
| 166 | 656 | *buf_size - pc->sync_offset); | |
| 167 | 656 | pc->index += *buf_size - pc->sync_offset; | |
| 168 | 656 | return -1; | |
| 169 | } else { | ||
| 170 | /* Found a possible frame start and a possible frame end */ | ||
| 171 | DiracParseUnit pu1, pu; | ||
| 172 | 154 | void *new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, | |
| 173 | 154 | pc->index + next); | |
| 174 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 154 times.
|
154 | if (!new_buffer) |
| 175 | 94 | return AVERROR(ENOMEM); | |
| 176 | 154 | pc->buffer = new_buffer; | |
| 177 | 154 | memcpy(pc->buffer + pc->index, *buf, next); | |
| 178 | 154 | pc->index += next; | |
| 179 | |||
| 180 | /* Need to check if we have a valid Parse Unit. We can't go by the | ||
| 181 | * sync pattern 'BBCD' alone because arithmetic coding of the residual | ||
| 182 | * and motion data can cause the pattern triggering a false start of | ||
| 183 | * frame. So check if the previous parse offset of the next parse unit | ||
| 184 | * is equal to the next parse offset of the current parse unit then | ||
| 185 | * we can be pretty sure that we have a valid parse unit */ | ||
| 186 |
2/4✓ Branch 1 taken 154 times.
✗ Branch 2 not taken.
✓ Branch 3 taken 154 times.
✗ Branch 4 not taken.
|
308 | if (!unpack_parse_unit(&pu1, pc, pc->index - 13) || |
| 187 | 154 | !unpack_parse_unit(&pu, pc, pc->index - 13 - pu1.prev_pu_offset) || | |
| 188 |
1/2✓ Branch 0 taken 154 times.
✗ Branch 1 not taken.
|
154 | pu.next_pu_offset != pu1.prev_pu_offset || |
| 189 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 154 times.
|
154 | pc->index < pc->dirac_unit_size + 13LL + pu1.prev_pu_offset |
| 190 | ) { | ||
| 191 | ✗ | pc->index -= 9; | |
| 192 | ✗ | *buf_size = next - 9; | |
| 193 | ✗ | pc->header_bytes_needed = 9; | |
| 194 | ✗ | return -1; | |
| 195 | } | ||
| 196 | |||
| 197 | /* All non-frame data must be accompanied by frame data. This is to | ||
| 198 | * ensure that pts is set correctly. So if the current parse unit is | ||
| 199 | * not frame data, wait for frame data to come along */ | ||
| 200 | |||
| 201 | 154 | pc->dirac_unit = pc->buffer + pc->index - 13 - | |
| 202 | 154 | pu1.prev_pu_offset - pc->dirac_unit_size; | |
| 203 | |||
| 204 | 154 | pc->dirac_unit_size += pu.next_pu_offset; | |
| 205 | |||
| 206 |
2/2✓ Branch 0 taken 94 times.
✓ Branch 1 taken 60 times.
|
154 | if ((pu.pu_type & 0x08) != 0x08) { |
| 207 | 94 | pc->header_bytes_needed = 9; | |
| 208 | 94 | *buf_size = next; | |
| 209 | 94 | return -1; | |
| 210 | } | ||
| 211 | |||
| 212 | /* Get the picture number to set the pts and dts*/ | ||
| 213 |
2/4✓ Branch 0 taken 60 times.
✗ Branch 1 not taken.
✓ Branch 2 taken 60 times.
✗ Branch 3 not taken.
|
60 | if (parse_timing_info && pu1.prev_pu_offset >= 13) { |
| 214 | 60 | uint8_t *cur_pu = pc->buffer + | |
| 215 | 60 | pc->index - 13 - pu1.prev_pu_offset; | |
| 216 | 60 | int64_t pts = AV_RB32(cur_pu + 13); | |
| 217 |
4/4✓ Branch 0 taken 4 times.
✓ Branch 1 taken 56 times.
✓ Branch 2 taken 2 times.
✓ Branch 3 taken 2 times.
|
60 | if (s->last_pts == 0 && s->last_dts == 0) |
| 218 | 2 | s->dts = pts - 1; | |
| 219 |
1/2✓ Branch 0 taken 58 times.
✗ Branch 1 not taken.
|
58 | else if (s->last_dts != AV_NOPTS_VALUE) |
| 220 | 58 | s->dts = s->last_dts + 1; | |
| 221 | 60 | s->pts = pts; | |
| 222 |
4/4✓ Branch 0 taken 32 times.
✓ Branch 1 taken 28 times.
✓ Branch 2 taken 1 times.
✓ Branch 3 taken 31 times.
|
60 | if (!avctx->has_b_frames && (cur_pu[4] & 0x03)) |
| 223 | 1 | avctx->has_b_frames = 1; | |
| 224 | } | ||
| 225 |
4/4✓ Branch 0 taken 29 times.
✓ Branch 1 taken 31 times.
✓ Branch 2 taken 21 times.
✓ Branch 3 taken 8 times.
|
60 | if (avctx->has_b_frames && s->pts == s->dts) |
| 226 | 21 | s->pict_type = AV_PICTURE_TYPE_B; | |
| 227 | |||
| 228 | /* Finally have a complete Dirac data unit */ | ||
| 229 | 60 | *buf = pc->dirac_unit; | |
| 230 | 60 | *buf_size = pc->dirac_unit_size; | |
| 231 | |||
| 232 | 60 | pc->dirac_unit_size = 0; | |
| 233 | 60 | pc->overread_index = pc->index - 13; | |
| 234 | 60 | pc->header_bytes_needed = 9; | |
| 235 | } | ||
| 236 | 60 | return next; | |
| 237 | } | ||
| 238 | |||
| 239 | 812 | static int dirac_parse(AVCodecParserContext *s, AVCodecContext *avctx, | |
| 240 | const uint8_t **poutbuf, int *poutbuf_size, | ||
| 241 | const uint8_t *buf, int buf_size) | ||
| 242 | { | ||
| 243 | 812 | DiracParseContext *pc = s->priv_data; | |
| 244 | int next; | ||
| 245 | |||
| 246 | 812 | *poutbuf = NULL; | |
| 247 | 812 | *poutbuf_size = 0; | |
| 248 | |||
| 249 |
1/2✗ Branch 0 not taken.
✓ Branch 1 taken 812 times.
|
812 | if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { |
| 250 | ✗ | next = buf_size; | |
| 251 | ✗ | *poutbuf = buf; | |
| 252 | ✗ | *poutbuf_size = buf_size; | |
| 253 | /* Assume that data has been packetized into an encapsulation unit. */ | ||
| 254 | } else { | ||
| 255 | 812 | next = find_frame_end(pc, buf, buf_size); | |
| 256 |
1/4✗ Branch 0 not taken.
✓ Branch 1 taken 812 times.
✗ Branch 2 not taken.
✗ Branch 3 not taken.
|
812 | if (!pc->is_synced && next == -1) |
| 257 | /* No frame start found yet. So throw away the entire buffer. */ | ||
| 258 | ✗ | return buf_size; | |
| 259 | |||
| 260 |
2/2✓ Branch 1 taken 750 times.
✓ Branch 2 taken 62 times.
|
812 | if (dirac_combine_frame(s, avctx, next, &buf, &buf_size) < 0) |
| 261 | 750 | return buf_size; | |
| 262 | } | ||
| 263 | |||
| 264 | 62 | *poutbuf = buf; | |
| 265 | 62 | *poutbuf_size = buf_size; | |
| 266 | 62 | return next; | |
| 267 | } | ||
| 268 | |||
| 269 | 35 | static av_cold void dirac_parse_close(AVCodecParserContext *s) | |
| 270 | { | ||
| 271 | 35 | DiracParseContext *pc = s->priv_data; | |
| 272 | |||
| 273 |
2/2✓ Branch 0 taken 2 times.
✓ Branch 1 taken 33 times.
|
35 | if (pc->buffer_size > 0) |
| 274 | 2 | av_freep(&pc->buffer); | |
| 275 | 35 | } | |
| 276 | |||
| 277 | const AVCodecParser ff_dirac_parser = { | ||
| 278 | .codec_ids = { AV_CODEC_ID_DIRAC }, | ||
| 279 | .priv_data_size = sizeof(DiracParseContext), | ||
| 280 | .parser_parse = dirac_parse, | ||
| 281 | .parser_close = dirac_parse_close, | ||
| 282 | }; | ||
| 283 |