/* * codec2 muxer and demuxers * Copyright (c) 2017 Tomas Härdin * * 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 "config_components.h" #include "libavcodec/codec2utils.h"#include "libavutil/channel_layout.h"#include "libavutil/intreadwrite.h"#include "libavutil/opt.h"#include "avio_internal.h"#include "avformat.h"#include "internal.h"#include "rawenc.h"#include "pcm.h" #define CODEC2_HEADER_SIZE 7#define CODEC2_MAGIC       0xC0DEC2 //the lowest version we should ever run across is 0.8//we may run across later versions as the format evolves#define EXPECTED_CODEC2_MAJOR_VERSION 0#define EXPECTED_CODEC2_MINOR_VERSION 8 typedef struct {    const AVClass *class;    int mode;    int frames_per_packet;} Codec2Context; static int codec2_probe(const AVProbeData *p){    //must start wih C0 DE C2    if (AV_RB24(p->buf) != CODEC2_MAGIC) {        return 0;    }     //no .c2 files prior to 0.8    //be strict about major version while we're at it    if (p->buf[3] != EXPECTED_CODEC2_MAJOR_VERSION ||        p->buf[4] <  EXPECTED_CODEC2_MINOR_VERSION) {        return 0;    }     //32 bits of identification -> low score    return AVPROBE_SCORE_EXTENSION + 1;} //Mimics codec2_samples_per_frame()static int codec2_mode_frame_size(AVFormatContext *s, int mode){    int frame_size_table[CODEC2_MODE_MAX+1] = {        160,    // 3200        160,    // 2400        320,    // 1600        320,    // 1400        320,    // 1300        320,    // 1200        320,    // 700        320,    // 700B        320,    // 700C    };     if (mode < 0 || mode > CODEC2_MODE_MAX) {        av_log(s, AV_LOG_ERROR, "unknown codec2 mode %i, can't find frame_size\n", mode);        return 0;    } else {        return frame_size_table[mode];    }} //Mimics (codec2_bits_per_frame()+7)/8static int codec2_mode_block_align(AVFormatContext *s, int mode){    int block_align_table[CODEC2_MODE_MAX+1] = {        8,      // 3200        6,      // 2400        8,      // 1600        7,      // 1400        7,      // 1300        6,      // 1200        4,      // 700        4,      // 700B        4,      // 700C    };     if (mode < 0 || mode > CODEC2_MODE_MAX) {        av_log(s, AV_LOG_ERROR, "unknown codec2 mode %i, can't find block_align\n", mode);        return 0;    } else {        return block_align_table[mode];    }} //Computes bitrate from mode, with frames rounded up to the nearest octet.//So 700 bit/s (28 bits/frame) becomes 800 bits/s (32 bits/frame).static int codec2_mode_bit_rate(AVFormatContext *s, int mode){    int frame_size  = codec2_mode_frame_size(s, mode);    int block_align = codec2_mode_block_align(s, mode);     if (frame_size <= 0 || block_align <= 0) {        return 0;    }     return 8 * 8000 * block_align / frame_size;} static int codec2_read_header_common(AVFormatContext *s, AVStream *st){    int mode = codec2_mode_from_extradata(st->codecpar->extradata);     st->codecpar->codec_type        = AVMEDIA_TYPE_AUDIO;    st->codecpar->codec_id          = AV_CODEC_ID_CODEC2;    st->codecpar->sample_rate       = 8000;    st->codecpar->format            = AV_SAMPLE_FMT_S16;    st->codecpar->ch_layout         = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;    st->codecpar->bit_rate          = codec2_mode_bit_rate(s, mode);    st->codecpar->frame_size        = codec2_mode_frame_size(s, mode);    st->codecpar->block_align       = codec2_mode_block_align(s, mode);     if (st->codecpar->bit_rate <= 0 ||        st->codecpar->frame_size <= 0 ||        st->codecpar->block_align <= 0) {        return AVERROR_INVALIDDATA;    }     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);     return 0;} static int codec2_read_header(AVFormatContext *s){    AVStream *st = avformat_new_stream(s, NULL);    int ret, version;     if (!st) {        return AVERROR(ENOMEM);    }     if (avio_rb24(s->pb) != CODEC2_MAGIC) {        av_log(s, AV_LOG_ERROR, "not a .c2 file\n");        return AVERROR_INVALIDDATA;    }     ret = ff_alloc_extradata(st->codecpar, CODEC2_EXTRADATA_SIZE);    if (ret) {        return ret;    }     ret = ffio_read_size(s->pb, st->codecpar->extradata, CODEC2_EXTRADATA_SIZE);    if (ret < 0) {        return ret;    }     version = AV_RB16(st->codecpar->extradata);    if ((version >> 8) != EXPECTED_CODEC2_MAJOR_VERSION) {        avpriv_report_missing_feature(s, "Major version %i", version >> 8);        return AVERROR_PATCHWELCOME;    }     ffformatcontext(s)->data_offset = CODEC2_HEADER_SIZE;     return codec2_read_header_common(s, st);} static int codec2_read_packet(AVFormatContext *s, AVPacket *pkt){    Codec2Context *c2 = s->priv_data;    AVStream *st = s->streams[0];    int ret, size, n, block_align, frame_size;     block_align = st->codecpar->block_align;    frame_size  = st->codecpar->frame_size;     if (block_align <= 0 || frame_size <= 0 || c2->frames_per_packet <= 0) {        return AVERROR(EINVAL);    }     //try to read desired number of frames, compute n from to actual number of bytes read    size = c2->frames_per_packet * block_align;    ret = av_get_packet(s->pb, pkt, size);    if (ret < 0) {        return ret;    }     //only set duration - compute_pkt_fields() and ff_pcm_read_seek() takes care of everything else    //tested by spamming the seek functionality in ffplay    n = ret / block_align;    pkt->duration = n * frame_size;     return ret;} static int codec2_write_header(AVFormatContext *s){    AVStream *st;     if (s->nb_streams != 1 || s->streams[0]->codecpar->codec_id != AV_CODEC_ID_CODEC2) {        av_log(s, AV_LOG_ERROR, ".c2 files must have exactly one codec2 stream\n");        return AVERROR(EINVAL);    }     st = s->streams[0];     if (st->codecpar->extradata_size != CODEC2_EXTRADATA_SIZE) {        av_log(s, AV_LOG_ERROR, ".c2 files require exactly %i bytes of extradata (got %i)\n",               CODEC2_EXTRADATA_SIZE, st->codecpar->extradata_size);        return AVERROR(EINVAL);    }     avio_wb24(s->pb, CODEC2_MAGIC);    avio_write(s->pb, st->codecpar->extradata, CODEC2_EXTRADATA_SIZE);     return 0;} static int codec2raw_read_header(AVFormatContext *s){    Codec2Context *c2 = s->priv_data;    AVStream *st;    int ret;     if (c2->mode < 0) {        //FIXME: using a default value of -1 for mandatory options is an incredibly ugly hack        av_log(s, AV_LOG_ERROR, "-mode must be set in order to make sense of raw codec2 files\n");        return AVERROR(EINVAL);    }     st = avformat_new_stream(s, NULL);    if (!st) {        return AVERROR(ENOMEM);    }     ret = ff_alloc_extradata(st->codecpar, CODEC2_EXTRADATA_SIZE);    if (ret) {        return ret;    }     codec2_make_extradata(st->codecpar->extradata, c2->mode);     return codec2_read_header_common(s, st);} //transcoding report2074.c2 to wav went from 7.391s to 5.322s with -frames_per_packet 1000 compared to default, same sha1sum#define FRAMES_PER_PACKET \    { "frames_per_packet", "Number of frames to read at a time. Higher = faster decoding, lower granularity", \      offsetof(Codec2Context, frames_per_packet), AV_OPT_TYPE_INT, {.i64 = 1}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM} static const AVOption codec2_options[] = {    FRAMES_PER_PACKET,    { NULL },}; static const AVOption codec2raw_options[] = {    CODEC2_AVOPTIONS("codec2 mode [mandatory]", Codec2Context, -1, -1, AV_OPT_FLAG_DECODING_PARAM),    FRAMES_PER_PACKET,    { NULL },}; static const AVClass codec2_demux_class = {    .class_name = "codec2 demuxer",    .item_name  = av_default_item_name,    .option     = codec2_options,    .version    = LIBAVUTIL_VERSION_INT,    .category   = AV_CLASS_CATEGORY_DEMUXER,}; static const AVClass codec2raw_demux_class = {    .class_name = "codec2raw demuxer",    .item_name  = av_default_item_name,    .option     = codec2raw_options,    .version    = LIBAVUTIL_VERSION_INT,    .category   = AV_CLASS_CATEGORY_DEMUXER,}; #if CONFIG_CODEC2_DEMUXERconst AVInputFormat ff_codec2_demuxer = {    .name           = "codec2",    .long_name      = NULL_IF_CONFIG_SMALL("codec2 .c2 demuxer"),    .priv_data_size = sizeof(Codec2Context),    .extensions     = "c2",    .read_probe     = codec2_probe,    .read_header    = codec2_read_header,    .read_packet    = codec2_read_packet,    .read_seek      = ff_pcm_read_seek,    .flags          = AVFMT_GENERIC_INDEX,    .raw_codec_id   = AV_CODEC_ID_CODEC2,    .priv_class     = &codec2_demux_class,};#endif #if CONFIG_CODEC2_MUXERconst AVOutputFormat ff_codec2_muxer = {    .name           = "codec2",    .long_name      = NULL_IF_CONFIG_SMALL("codec2 .c2 muxer"),    .priv_data_size = sizeof(Codec2Context),    .extensions     = "c2",    .audio_codec    = AV_CODEC_ID_CODEC2,    .video_codec    = AV_CODEC_ID_NONE,    .write_header   = codec2_write_header,    .write_packet   = ff_raw_write_packet,    .flags          = AVFMT_NOTIMESTAMPS,};#endif #if CONFIG_CODEC2RAW_DEMUXERconst AVInputFormat ff_codec2raw_demuxer = {    .name           = "codec2raw",    .long_name      = NULL_IF_CONFIG_SMALL("raw codec2 demuxer"),    .priv_data_size = sizeof(Codec2Context),    .read_header    = codec2raw_read_header,    .read_packet    = codec2_read_packet,    .read_seek      = ff_pcm_read_seek,    .flags          = AVFMT_GENERIC_INDEX,    .raw_codec_id   = AV_CODEC_ID_CODEC2,    .priv_class     = &codec2raw_demux_class,};#endif