/* * SBC parser * * Copyright (C) 2017  Aurelien Jacobs <aurel@gnuage.org> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "sbc.h"#include "parser.h" typedef struct SBCParseContext {    ParseContext pc;    uint8_t header[3];    int header_size;    int buffered_size;} SBCParseContext; static int sbc_parse_header(AVCodecParserContext *s, AVCodecContext *avctx,                            const uint8_t *data, size_t len){    static const int sample_rates[4] = { 16000, 32000, 44100, 48000 };    int sr, blocks, mode, subbands, bitpool, channels, joint;    int length;     if (len < 3)        return -1;     if (data[0] == MSBC_SYNCWORD && data[1] == 0 && data[2] == 0) {        avctx->channels = 1;        avctx->sample_rate = 16000;        avctx->frame_size = 120;        s->duration = avctx->frame_size;        return 57;    }     if (data[0] != SBC_SYNCWORD)        return -2;     sr       =   (data[1] >> 6) & 0x03;    blocks   = (((data[1] >> 4) & 0x03) + 1) << 2;    mode     =   (data[1] >> 2) & 0x03;    subbands = (((data[1] >> 0) & 0x01) + 1) << 2;    bitpool  = data[2];     channels = mode == SBC_MODE_MONO ? 1 : 2;    joint    = mode == SBC_MODE_JOINT_STEREO;     length = 4 + (subbands * channels) / 2             + ((((mode == SBC_MODE_DUAL_CHANNEL) + 1) * blocks * bitpool                 + (joint * subbands)) + 7) / 8;     avctx->channels = channels;    avctx->sample_rate = sample_rates[sr];    avctx->frame_size = subbands * blocks;    s->duration = avctx->frame_size;    return length;} static int sbc_parse(AVCodecParserContext *s, AVCodecContext *avctx,                     const uint8_t **poutbuf, int *poutbuf_size,                     const uint8_t *buf, int buf_size){    SBCParseContext *pc = s->priv_data;    int next;     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {        next = buf_size;    } else {        if (pc->header_size) {            memcpy(pc->header + pc->header_size, buf,                   sizeof(pc->header) - pc->header_size);            next = sbc_parse_header(s, avctx, pc->header, sizeof(pc->header))                 - pc->buffered_size;            pc->header_size = 0;        } else {            next = sbc_parse_header(s, avctx, buf, buf_size);            if (next >= buf_size)                next = -1;        }         if (next < 0) {            pc->header_size = FFMIN(sizeof(pc->header), buf_size);            memcpy(pc->header, buf, pc->header_size);            pc->buffered_size = buf_size;            next = END_NOT_FOUND;        }         if (ff_combine_frame(&pc->pc, next, &buf, &buf_size) < 0) {            *poutbuf      = NULL;            *poutbuf_size = 0;            return buf_size;        }    }     *poutbuf      = buf;    *poutbuf_size = buf_size;    return next;} AVCodecParser ff_sbc_parser = {    .codec_ids      = { AV_CODEC_ID_SBC },    .priv_data_size = sizeof(SBCParseContext),    .parser_parse   = sbc_parse,    .parser_close   = ff_parse_close,};