libavcodec/gsm_parser.c

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00001 /*
00002  * Copyright (c) 2012 Justin Ruggles
00003  *
00004  * This file is part of Libav.
00005  *
00006  * Libav is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * Libav is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with Libav; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00028 #include "parser.h"
00029 #include "gsm.h"
00030 
00031 typedef struct GSMParseContext {
00032 ParseContext pc;
00033 int block_size;
00034 int remaining;
00035 } GSMParseContext;
00036 
00037 static int gsm_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
00038 const uint8_t **poutbuf, int *poutbuf_size,
00039 const uint8_t *buf, int buf_size)
00040 {
00041 GSMParseContext *s = s1->priv_data;
00042 ParseContext *pc = &s->pc;
00043 int next;
00044 
00045 if (!s->block_size) {
00046 switch (avctx->codec_id) {
00047 case CODEC_ID_GSM: s->block_size = GSM_BLOCK_SIZE; break;
00048 case CODEC_ID_GSM_MS: s->block_size = GSM_MS_BLOCK_SIZE; break;
00049 default:
00050 return AVERROR(EINVAL);
00051 }
00052 }
00053 
00054 if (!s->remaining)
00055 s->remaining = s->block_size;
00056 if (s->remaining <= buf_size) {
00057 next = s->remaining;
00058 s->remaining = 0;
00059 } else {
00060 next = END_NOT_FOUND;
00061 s->remaining -= buf_size;
00062 }
00063 
00064 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
00065 *poutbuf = NULL;
00066 *poutbuf_size = 0;
00067 return buf_size;
00068 }
00069 *poutbuf = buf;
00070 *poutbuf_size = buf_size;
00071 return next;
00072 }
00073 
00074 AVCodecParser ff_gsm_parser = {
00075 .codec_ids = { CODEC_ID_GSM, CODEC_ID_GSM_MS },
00076 .priv_data_size = sizeof(GSMParseContext),
00077 .parser_parse = gsm_parse,
00078 .parser_close = ff_parse_close,
00079 };

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