From 57231e4d5b467833fb289439cd35a92513bb55c1 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Tue, 2 Oct 2012 13:43:19 +0000 Subject: tak: demuxer, parser, and decoder Signed-off-by: Paul B Mahol Signed-off-by: Justin Ruggles --- libavcodec/tak.c | 150 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 150 insertions(+) create mode 100644 libavcodec/tak.c (limited to 'libavcodec/tak.c') diff --git a/libavcodec/tak.c b/libavcodec/tak.c new file mode 100644 index 0000000000..867a84bc71 --- /dev/null +++ b/libavcodec/tak.c @@ -0,0 +1,150 @@ +/* + * TAK common code + * Copyright (c) 2012 Paul B Mahol + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "libavutil/bswap.h" +#include "libavutil/crc.h" +#include "libavutil/intreadwrite.h" +#include "tak.h" + +static const uint16_t frame_duration_type_quants[] = { + 3, 4, 6, 8, 4096, 8192, 16384, 512, 1024, 2048, +}; + +static int tak_get_nb_samples(int sample_rate, enum TAKFrameSizeType type) +{ + int nb_samples, max_nb_samples; + + if (type <= TAK_FST_250ms) { + nb_samples = sample_rate * frame_duration_type_quants[type] >> + TAK_FRAME_DURATION_QUANT_SHIFT; + max_nb_samples = 16384; + } else if (type < FF_ARRAY_ELEMS(frame_duration_type_quants)) { + nb_samples = frame_duration_type_quants[type]; + max_nb_samples = sample_rate * + frame_duration_type_quants[TAK_FST_250ms] >> + TAK_FRAME_DURATION_QUANT_SHIFT; + } else { + return AVERROR_INVALIDDATA; + } + + if (nb_samples <= 0 || nb_samples > max_nb_samples) + return AVERROR_INVALIDDATA; + + return nb_samples; +} + +static int crc_init = 0; +#if CONFIG_SMALL +#define CRC_TABLE_SIZE 257 +#else +#define CRC_TABLE_SIZE 1024 +#endif +static AVCRC crc_24[CRC_TABLE_SIZE]; + +av_cold void ff_tak_init_crc(void) +{ + if (!crc_init) { + av_crc_init(crc_24, 0, 24, 0x864CFBU, sizeof(crc_24)); + crc_init = 1; + } +} + +int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size) +{ + uint32_t crc, CRC; + + if (buf_size < 4) + return AVERROR_INVALIDDATA; + buf_size -= 3; + + CRC = av_bswap32(AV_RL24(buf + buf_size)) >> 8; + crc = av_crc(crc_24, 0xCE04B7U, buf, buf_size); + if (CRC != crc) + return AVERROR_INVALIDDATA; + + return 0; +} + +void avpriv_tak_parse_streaminfo(GetBitContext *gb, TAKStreamInfo *s) +{ + uint64_t channel_mask = 0; + int frame_type, i; + + s->codec = get_bits(gb, TAK_ENCODER_CODEC_BITS); + skip_bits(gb, TAK_ENCODER_PROFILE_BITS); + + frame_type = get_bits(gb, TAK_SIZE_FRAME_DURATION_BITS); + s->samples = get_bits64(gb, TAK_SIZE_SAMPLES_NUM_BITS); + + s->data_type = get_bits(gb, TAK_FORMAT_DATA_TYPE_BITS); + s->sample_rate = get_bits(gb, TAK_FORMAT_SAMPLE_RATE_BITS) + + TAK_SAMPLE_RATE_MIN; + s->bps = get_bits(gb, TAK_FORMAT_BPS_BITS) + + TAK_BPS_MIN; + s->channels = get_bits(gb, TAK_FORMAT_CHANNEL_BITS) + + TAK_CHANNELS_MIN; + + if (get_bits1(gb)) { + skip_bits(gb, TAK_FORMAT_VALID_BITS); + if (get_bits1(gb)) { + for (i = 0; i < s->channels; i++) { + int value = get_bits(gb, TAK_FORMAT_CH_LAYOUT_BITS); + + if (value > 0 && value <= 18) + channel_mask |= 1 << (value - 1); + } + } + } + + s->ch_layout = channel_mask; + s->frame_samples = tak_get_nb_samples(s->sample_rate, frame_type); +} + +int ff_tak_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb, + TAKStreamInfo *ti, int log_level_offset) +{ + if (get_bits(gb, TAK_FRAME_HEADER_SYNC_ID_BITS) != TAK_FRAME_HEADER_SYNC_ID) { + av_log(avctx, AV_LOG_ERROR + log_level_offset, "missing sync id\n"); + return AVERROR_INVALIDDATA; + } + + ti->flags = get_bits(gb, TAK_FRAME_HEADER_FLAGS_BITS); + ti->frame_num = get_bits(gb, TAK_FRAME_HEADER_NO_BITS); + + if (ti->flags & TAK_FRAME_FLAG_IS_LAST) { + ti->last_frame_samples = get_bits(gb, TAK_FRAME_HEADER_SAMPLE_COUNT_BITS) + 1; + skip_bits(gb, 2); + } else { + ti->last_frame_samples = 0; + } + + if (ti->flags & TAK_FRAME_FLAG_HAS_INFO) { + avpriv_tak_parse_streaminfo(gb, ti); + + if (get_bits(gb, 6)) + skip_bits(gb, 25); + align_get_bits(gb); + } + + skip_bits(gb, 24); + + return 0; +} -- cgit v1.2.3