From 2505ebc632d4f3650d6082c58a8809faeb1ee832 Mon Sep 17 00:00:00 2001 From: Aurelien Jacobs Date: Sat, 12 Aug 2017 02:35:06 +0200 Subject: sbc: add parser for SBC --- libavcodec/sbc_parser.c | 122 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) create mode 100644 libavcodec/sbc_parser.c (limited to 'libavcodec/sbc_parser.c') diff --git a/libavcodec/sbc_parser.c b/libavcodec/sbc_parser.c new file mode 100644 index 0000000000..f56564147a --- /dev/null +++ b/libavcodec/sbc_parser.c @@ -0,0 +1,122 @@ +/* + * SBC parser + * + * Copyright (C) 2017 Aurelien Jacobs + * + * 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_fmt = AV_SAMPLE_FMT_S16; + 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_fmt = AV_SAMPLE_FMT_S16; + 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, +}; -- cgit v1.2.3