blob: 1054a30ca919fa9fe17d8fcf48c1135cd3657e4f
| 1 | /* |
| 2 | * Copyright (c) 2012 Justin Ruggles |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | /** |
| 22 | * @file |
| 23 | * GSM audio parser |
| 24 | * |
| 25 | * Splits packets into individual blocks. |
| 26 | */ |
| 27 | |
| 28 | #include "libavutil/avassert.h" |
| 29 | #include "parser.h" |
| 30 | #include "gsm.h" |
| 31 | |
| 32 | typedef struct GSMParseContext { |
| 33 | ParseContext pc; |
| 34 | int block_size; |
| 35 | int duration; |
| 36 | int remaining; |
| 37 | } GSMParseContext; |
| 38 | |
| 39 | static int gsm_parse(AVCodecParserContext *s1, AVCodecContext *avctx, |
| 40 | const uint8_t **poutbuf, int *poutbuf_size, |
| 41 | const uint8_t *buf, int buf_size) |
| 42 | { |
| 43 | GSMParseContext *s = s1->priv_data; |
| 44 | ParseContext *pc = &s->pc; |
| 45 | int next; |
| 46 | |
| 47 | if (!s->block_size) { |
| 48 | switch (avctx->codec_id) { |
| 49 | case AV_CODEC_ID_GSM: |
| 50 | s->block_size = GSM_BLOCK_SIZE; |
| 51 | s->duration = GSM_FRAME_SIZE; |
| 52 | break; |
| 53 | case AV_CODEC_ID_GSM_MS: |
| 54 | s->block_size = avctx->block_align ? avctx->block_align |
| 55 | : GSM_MS_BLOCK_SIZE; |
| 56 | s->duration = GSM_FRAME_SIZE * 2; |
| 57 | break; |
| 58 | default: |
| 59 | av_assert0(0); |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | if (!s->remaining) |
| 64 | s->remaining = s->block_size; |
| 65 | if (s->remaining <= buf_size) { |
| 66 | next = s->remaining; |
| 67 | s->remaining = 0; |
| 68 | } else { |
| 69 | next = END_NOT_FOUND; |
| 70 | s->remaining -= buf_size; |
| 71 | } |
| 72 | |
| 73 | if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) { |
| 74 | *poutbuf = NULL; |
| 75 | *poutbuf_size = 0; |
| 76 | return buf_size; |
| 77 | } |
| 78 | |
| 79 | s1->duration = s->duration; |
| 80 | |
| 81 | *poutbuf = buf; |
| 82 | *poutbuf_size = buf_size; |
| 83 | return next; |
| 84 | } |
| 85 | |
| 86 | AVCodecParser ff_gsm_parser = { |
| 87 | .codec_ids = { AV_CODEC_ID_GSM, AV_CODEC_ID_GSM_MS }, |
| 88 | .priv_data_size = sizeof(GSMParseContext), |
| 89 | .parser_parse = gsm_parse, |
| 90 | .parser_close = ff_parse_close, |
| 91 | }; |
| 92 |