PeerStreamer

/*

 * NUT (de)muxing via libnut

 * copyright (c) 2006 Oded Shimon <ods15@ods15.dyndns.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

 */

/**

 * @file

 * NUT demuxing and muxing via libnut.

 * @author Oded Shimon <ods15@ods15.dyndns.org>

 */

#include "avformat.h"

#include "riff.h"

#include <libnut.h>

#define ID_STRING "nut/multimedia container"

#define ID_LENGTH (strlen(ID_STRING) + 1)

typedef struct {

    nut_context_tt * nut;

    nut_stream_header_tt * s;

} NUTContext;

static const AVCodecTag nut_tags[] = {

    { CODEC_ID_MPEG4,  MKTAG('m', 'p', '4', 'v') },

    { CODEC_ID_MP3,    MKTAG('m', 'p', '3', ' ') },

    { CODEC_ID_VORBIS, MKTAG('v', 'r', 'b', 's') },

    { 0, 0 },

};

#if CONFIG_LIBNUT_MUXER

static int av_write(void * h, size_t len, const uint8_t * buf) {

    AVIOContext * bc = h;

    avio_write(bc, buf, len);

    //avio_flush(bc);

    return len;

}

static int nut_write_header(AVFormatContext * avf) {

    NUTContext * priv = avf->priv_data;

    AVIOContext * bc = avf->pb;

    nut_muxer_opts_tt mopts = {

        .output = {

            .priv = bc,

            .write = av_write,

        },

        .alloc = { av_malloc, av_realloc, av_free },

        .write_index = 1,

        .realtime_stream = 0,

        .max_distance = 32768,

        .fti = NULL,

    };

    nut_stream_header_tt * s;

    int i;

    priv->s = s = av_mallocz((avf->nb_streams + 1) * sizeof*s);

    for (i = 0; i < avf->nb_streams; i++) {

        AVCodecContext * codec = avf->streams[i]->codec;

        int j;

        int fourcc = 0;

        int num, denom, ssize;

        s[i].type = codec->codec_type == AVMEDIA_TYPE_VIDEO ? NUT_VIDEO_CLASS : NUT_AUDIO_CLASS;

        if (codec->codec_tag) fourcc = codec->codec_tag;

        else fourcc = ff_codec_get_tag(nut_tags, codec->codec_id);

        if (!fourcc) {

            if (codec->codec_type == AVMEDIA_TYPE_VIDEO) fourcc = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);

            if (codec->codec_type == AVMEDIA_TYPE_AUDIO) fourcc = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);

        }

        s[i].fourcc_len = 4;

        s[i].fourcc = av_malloc(s[i].fourcc_len);

        for (j = 0; j < s[i].fourcc_len; j++) s[i].fourcc[j] = (fourcc >> (j*8)) & 0xFF;

        ff_parse_specific_params(codec, &num, &ssize, &denom);

        av_set_pts_info(avf->streams[i], 60, denom, num);

        s[i].time_base.num = denom;

        s[i].time_base.den = num;

        s[i].fixed_fps = 0;

        s[i].decode_delay = codec->has_b_frames;

        s[i].codec_specific_len = codec->extradata_size;

        s[i].codec_specific = codec->extradata;

        if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {

            s[i].width = codec->width;

            s[i].height = codec->height;

            s[i].sample_width = 0;

            s[i].sample_height = 0;

            s[i].colorspace_type = 0;

        } else {

            s[i].samplerate_num = codec->sample_rate;

            s[i].samplerate_denom = 1;

            s[i].channel_count = codec->channels;

        }

    }

    s[avf->nb_streams].type = -1;

    priv->nut = nut_muxer_init(&mopts, s, NULL);

    return 0;

}

static int nut_write_packet(AVFormatContext * avf, AVPacket * pkt) {

    NUTContext * priv = avf->priv_data;

    nut_packet_tt p;

    p.len = pkt->size;

    p.stream = pkt->stream_index;

    p.pts = pkt->pts;

    p.flags = pkt->flags & AV_PKT_FLAG_KEY ? NUT_FLAG_KEY : 0;

    p.next_pts = 0;

    nut_write_frame_reorder(priv->nut, &p, pkt->data);

    return 0;

}

static int nut_write_trailer(AVFormatContext * avf) {

    AVIOContext * bc = avf->pb;

    NUTContext * priv = avf->priv_data;

    int i;

    nut_muxer_uninit_reorder(priv->nut);

    avio_flush(bc);

    for(i = 0; priv->s[i].type != -1; i++ ) av_freep(&priv->s[i].fourcc);

    av_freep(&priv->s);

    return 0;

}

AVOutputFormat ff_libnut_muxer = {

    "libnut",

    "nut format",

    "video/x-nut",

    "nut",

    sizeof(NUTContext),

    CODEC_ID_VORBIS,

    CODEC_ID_MPEG4,

    nut_write_header,

    nut_write_packet,

    nut_write_trailer,

    .flags = AVFMT_GLOBALHEADER,

};

#endif /* CONFIG_LIBNUT_MUXER */

static int nut_probe(AVProbeData *p) {

    if (!memcmp(p->buf, ID_STRING, ID_LENGTH)) return AVPROBE_SCORE_MAX;

    return 0;

}

static size_t av_read(void * h, size_t len, uint8_t * buf) {

    AVIOContext * bc = h;

    return avio_read(bc, buf, len);

}

static off_t av_seek(void * h, long long pos, int whence) {

    AVIOContext * bc = h;

    if (whence == SEEK_END) {

        pos = avio_size(bc) + pos;

        whence = SEEK_SET;

    }

    return avio_seek(bc, pos, whence);

}

static int nut_read_header(AVFormatContext * avf, AVFormatParameters * ap) {

    NUTContext * priv = avf->priv_data;

    AVIOContext * bc = avf->pb;

    nut_demuxer_opts_tt dopts = {

        .input = {

            .priv = bc,

            .seek = av_seek,

            .read = av_read,

            .eof = NULL,

            .file_pos = 0,

        },

        .alloc = { av_malloc, av_realloc, av_free },

        .read_index = 1,

        .cache_syncpoints = 1,

    };

    nut_context_tt * nut = priv->nut = nut_demuxer_init(&dopts);

    nut_stream_header_tt * s;

    int ret, i;

    if ((ret = nut_read_headers(nut, &s, NULL))) {

        av_log(avf, AV_LOG_ERROR, " NUT error: %s\n", nut_error(ret));

        nut_demuxer_uninit(nut);

        return -1;

    }

    priv->s = s;

    for (i = 0; s[i].type != -1 && i < 2; i++) {

        AVStream * st = av_new_stream(avf, i);

        int j;

        for (j = 0; j < s[i].fourcc_len && j < 8; j++) st->codec->codec_tag |= s[i].fourcc[j]<<(j*8);

        st->codec->has_b_frames = s[i].decode_delay;

        st->codec->extradata_size = s[i].codec_specific_len;

        if (st->codec->extradata_size) {

            st->codec->extradata = av_mallocz(st->codec->extradata_size);

            memcpy(st->codec->extradata, s[i].codec_specific, st->codec->extradata_size);

        }

        av_set_pts_info(avf->streams[i], 60, s[i].time_base.num, s[i].time_base.den);

        st->start_time = 0;

        st->duration = s[i].max_pts;

        st->codec->codec_id = ff_codec_get_id(nut_tags, st->codec->codec_tag);

        switch(s[i].type) {

        case NUT_AUDIO_CLASS:

            st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

            if (st->codec->codec_id == CODEC_ID_NONE) st->codec->codec_id = ff_codec_get_id(ff_codec_wav_tags, st->codec->codec_tag);

            st->codec->channels = s[i].channel_count;

            st->codec->sample_rate = s[i].samplerate_num / s[i].samplerate_denom;

            break;

        case NUT_VIDEO_CLASS:

            st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

            if (st->codec->codec_id == CODEC_ID_NONE) st->codec->codec_id = ff_codec_get_id(ff_codec_bmp_tags, st->codec->codec_tag);

            st->codec->width = s[i].width;

            st->codec->height = s[i].height;

            st->sample_aspect_ratio.num = s[i].sample_width;

            st->sample_aspect_ratio.den = s[i].sample_height;

            break;

        }

        if (st->codec->codec_id == CODEC_ID_NONE) av_log(avf, AV_LOG_ERROR, "Unknown codec?!\n");

    }

    return 0;

}

static int nut_read_packet(AVFormatContext * avf, AVPacket * pkt) {

    NUTContext * priv = avf->priv_data;

    nut_packet_tt pd;

    int ret;

    ret = nut_read_next_packet(priv->nut, &pd);

    if (ret || av_new_packet(pkt, pd.len) < 0) {

        if (ret != NUT_ERR_EOF)

            av_log(avf, AV_LOG_ERROR, " NUT error: %s\n", nut_error(ret));

        return -1;

    }

    if (pd.flags & NUT_FLAG_KEY) pkt->flags |= AV_PKT_FLAG_KEY;

    pkt->pts = pd.pts;

    pkt->stream_index = pd.stream;

    pkt->pos = avio_tell(avf->pb);

    ret = nut_read_frame(priv->nut, &pd.len, pkt->data);

    return ret;

}

static int nut_read_seek(AVFormatContext * avf, int stream_index, int64_t target_ts, int flags) {

    NUTContext * priv = avf->priv_data;

    int active_streams[] = { stream_index, -1 };

    double time_pos = target_ts * priv->s[stream_index].time_base.num / (double)priv->s[stream_index].time_base.den;

    if (nut_seek(priv->nut, time_pos, 2*!(flags & AVSEEK_FLAG_BACKWARD), active_streams)) return -1;

    return 0;

}

static int nut_read_close(AVFormatContext *s) {

    NUTContext * priv = s->priv_data;

    nut_demuxer_uninit(priv->nut);

    return 0;

}

AVInputFormat ff_libnut_demuxer = {

    "libnut",

    NULL_IF_CONFIG_SMALL("NUT format"),

    sizeof(NUTContext),

    nut_probe,

    nut_read_header,

    nut_read_packet,

    nut_read_close,

    nut_read_seek,

    .extensions = "nut",

};