yading@10: /*
yading@10:  * Copyright (c) 2011  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:  * ADX audio parser
yading@10:  *
yading@10:  * Splits packets into individual blocks.
yading@10:  */
yading@10: 
yading@10: #include "libavutil/intreadwrite.h"
yading@10: #include "parser.h"
yading@10: #include "adx.h"
yading@10: 
yading@10: typedef struct ADXParseContext {
yading@10:     ParseContext pc;
yading@10:     int header_size;
yading@10:     int block_size;
yading@10:     int remaining;
yading@10: } ADXParseContext;
yading@10: 
yading@10: static int adx_parse(AVCodecParserContext *s1,
yading@10:                            AVCodecContext *avctx,
yading@10:                            const uint8_t **poutbuf, int *poutbuf_size,
yading@10:                            const uint8_t *buf, int buf_size)
yading@10: {
yading@10:     ADXParseContext *s = s1->priv_data;
yading@10:     ParseContext *pc = &s->pc;
yading@10:     int next = END_NOT_FOUND;
yading@10:     int i;
yading@10:     uint64_t state = pc->state64;
yading@10: 
yading@10:     if (!s->header_size) {
yading@10:         for (i = 0; i < buf_size; i++) {
yading@10:             state = (state << 8) | buf[i];
yading@10:             /* check for fixed fields in ADX header for possible match */
yading@10:             if ((state & 0xFFFF0000FFFFFF00) == 0x8000000003120400ULL) {
yading@10:                 int channels    = state & 0xFF;
yading@10:                 int header_size = ((state >> 32) & 0xFFFF) + 4;
yading@10:                 if (channels > 0 && header_size >= 8) {
yading@10:                     s->header_size = header_size;
yading@10:                     s->block_size  = BLOCK_SIZE * channels;
yading@10:                     s->remaining   = i - 7 + s->header_size + s->block_size;
yading@10:                     break;
yading@10:                 }
yading@10:             }
yading@10:         }
yading@10:         pc->state64 = state;
yading@10:     }
yading@10: 
yading@10:     if (s->header_size) {
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:             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 = BLOCK_SAMPLES;
yading@10: 
yading@10:     *poutbuf = buf;
yading@10:     *poutbuf_size = buf_size;
yading@10:     return next;
yading@10: }
yading@10: 
yading@10: AVCodecParser ff_adx_parser = {
yading@10:     .codec_ids      = { AV_CODEC_ID_ADPCM_ADX },
yading@10:     .priv_data_size = sizeof(ADXParseContext),
yading@10:     .parser_parse   = adx_parse,
yading@10:     .parser_close   = ff_parse_close,
yading@10: };