yading@10: /*
yading@10:  * Copyright (c) 2012  Justin Ruggles
yading@10:  *
yading@10:  * This file is part of Libav.
yading@10:  *
yading@10:  * Libav is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * Libav is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with Libav; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * GSM audio parser
yading@10:  *
yading@10:  * Splits packets into individual blocks.
yading@10:  */
yading@10: 
yading@10: #include "parser.h"
yading@10: #include "gsm.h"
yading@10: 
yading@10: typedef struct GSMParseContext {
yading@10:     ParseContext pc;
yading@10:     int block_size;
yading@10:     int duration;
yading@10:     int remaining;
yading@10: } GSMParseContext;
yading@10: 
yading@10: static int gsm_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
yading@10:                      const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                      const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     GSMParseContext *s = s1->priv_data;
yading@10:     ParseContext *pc = &s->pc;
yading@10:     int next;
yading@10: 
yading@10:     if (!s->block_size) {
yading@10:         switch (avctx->codec_id) {
yading@10:         case AV_CODEC_ID_GSM:
yading@10:             s->block_size = GSM_BLOCK_SIZE;
yading@10:             s->duration   = GSM_FRAME_SIZE;
yading@10:             break;
yading@10:         case AV_CODEC_ID_GSM_MS:
yading@10:             s->block_size = GSM_MS_BLOCK_SIZE;
yading@10:             s->duration   = GSM_FRAME_SIZE * 2;
yading@10:             break;
yading@10:         default:
yading@10:             *poutbuf      = buf;
yading@10:             *poutbuf_size = buf_size;
yading@10:             av_log(avctx, AV_LOG_ERROR, "Invalid codec_id\n");
yading@10:             return buf_size;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     if (!s->remaining)
yading@10:         s->remaining = s->block_size;
yading@10:     if (s->remaining <= buf_size) {
yading@10:         next = s->remaining;
yading@10:         s->remaining = 0;
yading@10:     } else {
yading@10:         next = END_NOT_FOUND;
yading@10:         s->remaining -= buf_size;
yading@10:     }
yading@10: 
yading@10:     if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
yading@10:         *poutbuf      = NULL;
yading@10:         *poutbuf_size = 0;
yading@10:         return buf_size;
yading@10:     }
yading@10: 
yading@10:     s1->duration = s->duration;
yading@10: 
yading@10:     *poutbuf      = buf;
yading@10:     *poutbuf_size = buf_size;
yading@10:     return next;
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_gsm_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_GSM, AV_CODEC_ID_GSM_MS },
yading@10:     .priv_data_size = sizeof(GSMParseContext),
yading@10:     .parser_parse   = gsm_parse,
yading@10:     .parser_close   = ff_parse_close,
yading@10: };