PeerStreamer

/*

 * GXF muxer.

 * Copyright (c) 2006 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>

 *

 * 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 "avformat.h"

#include "gxf.h"

#include "riff.h"

#include "audiointerleave.h"

#define GXF_AUDIO_PACKET_SIZE 65536

typedef struct GXFStreamContext {

    AudioInterleaveContext aic;

    uint32_t track_type;

    uint32_t sample_size;

    uint32_t sample_rate;

    uint16_t media_type;

    uint16_t media_info;

    int frame_rate_index;

    int lines_index;

    int fields;

    int iframes;

    int pframes;

    int bframes;

    int p_per_gop;

    int b_per_i_or_p; ///< number of B frames per I frame or P frame

    int first_gop_closed;

    unsigned order;   ///< interleaving order

} GXFStreamContext;

typedef struct GXFContext {

    uint32_t nb_fields;

    uint16_t audio_tracks;

    uint16_t mpeg_tracks;

    int64_t creation_time;

    uint32_t umf_start_offset;

    uint32_t umf_track_offset;

    uint32_t umf_media_offset;

    uint32_t umf_length;

    uint16_t umf_track_size;

    uint16_t umf_media_size;

    AVRational time_base;

    int flags;

    GXFStreamContext timecode_track;

    unsigned *flt_entries;    ///< offsets of packets /1024, starts after 2nd video field

    unsigned flt_entries_nb;

    uint64_t *map_offsets;    ///< offset of map packets

    unsigned map_offsets_nb;

    unsigned packet_count;

} GXFContext;

static const struct {

    int height, index;

} gxf_lines_tab[] = {

    { 480,  1 }, /* NTSC */

    { 512,  1 }, /* NTSC + VBI */

    { 576,  2 }, /* PAL */

    { 608,  2 }, /* PAL + VBI */

    { 1080, 4 },

    { 720,  6 },

};

static const AVCodecTag gxf_media_types[] = {

    { CODEC_ID_MJPEG     ,   3 }, /* NTSC */

    { CODEC_ID_MJPEG     ,   4 }, /* PAL */

    { CODEC_ID_PCM_S24LE ,   9 },

    { CODEC_ID_PCM_S16LE ,  10 },

    { CODEC_ID_MPEG2VIDEO,  11 }, /* NTSC */

    { CODEC_ID_MPEG2VIDEO,  12 }, /* PAL */

    { CODEC_ID_DVVIDEO   ,  13 }, /* NTSC */

    { CODEC_ID_DVVIDEO   ,  14 }, /* PAL */

    { CODEC_ID_DVVIDEO   ,  15 }, /* 50M NTSC */

    { CODEC_ID_DVVIDEO   ,  16 }, /* 50M PAL */

    { CODEC_ID_AC3       ,  17 },

    //{ CODEC_ID_NONE,  ,   18 }, /* Non compressed 24 bit audio */

    { CODEC_ID_MPEG2VIDEO,  20 }, /* MPEG HD */

    { CODEC_ID_MPEG1VIDEO,  22 }, /* NTSC */

    { CODEC_ID_MPEG1VIDEO,  23 }, /* PAL */

    { CODEC_ID_NONE,         0 },

};

#define SERVER_PATH "EXT:/PDR/default/"

#define ES_NAME_PATTERN "EXT:/PDR/default/ES."

static int gxf_find_lines_index(AVStream *st)

{

    GXFStreamContext *sc = st->priv_data;

    int i;

    for (i = 0; i < 6; ++i) {

        if (st->codec->height == gxf_lines_tab[i].height) {

            sc->lines_index = gxf_lines_tab[i].index;

            return 0;

        }

    }

    return -1;

}

static void gxf_write_padding(AVIOContext *pb, int64_t to_pad)

{

    for (; to_pad > 0; to_pad--) {

        avio_w8(pb, 0);

    }

}

static int64_t updatePacketSize(AVIOContext *pb, int64_t pos)

{

    int64_t curpos;

    int size;

    size = avio_tell(pb) - pos;

    if (size % 4) {

        gxf_write_padding(pb, 4 - size % 4);

        size = avio_tell(pb) - pos;

    }

    curpos = avio_tell(pb);

    avio_seek(pb, pos + 6, SEEK_SET);

    avio_wb32(pb, size);

    avio_seek(pb, curpos, SEEK_SET);

    return curpos - pos;

}

static int64_t updateSize(AVIOContext *pb, int64_t pos)

{

    int64_t curpos;

    curpos = avio_tell(pb);

    avio_seek(pb, pos, SEEK_SET);

    avio_wb16(pb, curpos - pos - 2);

    avio_seek(pb, curpos, SEEK_SET);

    return curpos - pos;

}

static void gxf_write_packet_header(AVIOContext *pb, GXFPktType type)

{

    avio_wb32(pb, 0);  /* packet leader for synchro */

    avio_w8(pb, 1);

    avio_w8(pb, type); /* map packet */

    avio_wb32(pb, 0);  /* size */

    avio_wb32(pb, 0);  /* reserved */

    avio_w8(pb, 0xE1); /* trailer 1 */

    avio_w8(pb, 0xE2); /* trailer 2 */

}

static int gxf_write_mpeg_auxiliary(AVIOContext *pb, AVStream *st)

{

    GXFStreamContext *sc = st->priv_data;

    char buffer[1024];

    int size, starting_line;

    if (sc->iframes) {

        sc->p_per_gop = sc->pframes / sc->iframes;

        if (sc->pframes % sc->iframes)

            sc->p_per_gop++;

        if (sc->pframes) {

            sc->b_per_i_or_p = sc->bframes / sc->pframes;

            if (sc->bframes % sc->pframes)

                sc->b_per_i_or_p++;

        }

        if (sc->p_per_gop > 9)

            sc->p_per_gop = 9; /* ensure value won't take more than one char */

        if (sc->b_per_i_or_p > 9)

            sc->b_per_i_or_p = 9; /* ensure value won't take more than one char */

    }

    if (st->codec->height == 512 || st->codec->height == 608)

        starting_line = 7; // VBI

    else if (st->codec->height == 480)

        starting_line = 20;

    else

        starting_line = 23; // default PAL

    size = snprintf(buffer, 1024, "Ver 1\nBr %.6f\nIpg 1\nPpi %d\nBpiop %d\n"

                    "Pix 0\nCf %d\nCg %d\nSl %d\nnl16 %d\nVi 1\nf1 1\n",

                    (float)st->codec->bit_rate, sc->p_per_gop, sc->b_per_i_or_p,

                    st->codec->pix_fmt == PIX_FMT_YUV422P ? 2 : 1, sc->first_gop_closed == 1,

                    starting_line, (st->codec->height + 15) / 16);

    avio_w8(pb, TRACK_MPG_AUX);

    avio_w8(pb, size + 1);

    avio_write(pb, (uint8_t *)buffer, size + 1);

    return size + 3;

}

static int gxf_write_timecode_auxiliary(AVIOContext *pb, GXFStreamContext *sc)

{

    avio_w8(pb, 0); /* fields */

    avio_w8(pb, 0); /* seconds */

    avio_w8(pb, 0); /* minutes */

    avio_w8(pb, 0); /* flags + hours */

    /* reserved */

    avio_wb32(pb, 0);

    return 8;

}

static int gxf_write_track_description(AVFormatContext *s, GXFStreamContext *sc, int index)

{

    AVIOContext *pb = s->pb;

    int64_t pos;

    int mpeg = sc->track_type == 4 || sc->track_type == 9;

    /* track description section */

    avio_w8(pb, sc->media_type + 0x80);

    avio_w8(pb, index + 0xC0);

    pos = avio_tell(pb);

    avio_wb16(pb, 0); /* size */

    /* media file name */

    avio_w8(pb, TRACK_NAME);

    avio_w8(pb, strlen(ES_NAME_PATTERN) + 3);

    avio_write(pb, ES_NAME_PATTERN, sizeof(ES_NAME_PATTERN) - 1);

    avio_wb16(pb, sc->media_info);

    avio_w8(pb, 0);

    if (!mpeg) {

        /* auxiliary information */

        avio_w8(pb, TRACK_AUX);

        avio_w8(pb, 8);

        if (sc->track_type == 3)

            gxf_write_timecode_auxiliary(pb, sc);

        else

            avio_wl64(pb, 0);

    }

    /* file system version */

    avio_w8(pb, TRACK_VER);

    avio_w8(pb, 4);

    avio_wb32(pb, 0);

    if (mpeg)

        gxf_write_mpeg_auxiliary(pb, s->streams[index]);

    /* frame rate */

    avio_w8(pb, TRACK_FPS);

    avio_w8(pb, 4);

    avio_wb32(pb, sc->frame_rate_index);

    /* lines per frame */

    avio_w8(pb, TRACK_LINES);

    avio_w8(pb, 4);

    avio_wb32(pb, sc->lines_index);

    /* fields per frame */

    avio_w8(pb, TRACK_FPF);

    avio_w8(pb, 4);

    avio_wb32(pb, sc->fields);

    return updateSize(pb, pos);

}

static int gxf_write_material_data_section(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos;

    int len;

    const char *filename = strrchr(s->filename, '/');

    pos = avio_tell(pb);

    avio_wb16(pb, 0); /* size */

    /* name */

    if (filename)

        filename++;

    else

        filename = s->filename;

    len = strlen(filename);

    avio_w8(pb, MAT_NAME);

    avio_w8(pb, strlen(SERVER_PATH) + len + 1);

    avio_write(pb, SERVER_PATH, sizeof(SERVER_PATH) - 1);

    avio_write(pb, filename, len);

    avio_w8(pb, 0);

    /* first field */

    avio_w8(pb, MAT_FIRST_FIELD);

    avio_w8(pb, 4);

    avio_wb32(pb, 0);

    /* last field */

    avio_w8(pb, MAT_LAST_FIELD);

    avio_w8(pb, 4);

    avio_wb32(pb, gxf->nb_fields);

    /* reserved */

    avio_w8(pb, MAT_MARK_IN);

    avio_w8(pb, 4);

    avio_wb32(pb, 0);

    avio_w8(pb, MAT_MARK_OUT);

    avio_w8(pb, 4);

    avio_wb32(pb, gxf->nb_fields);

    /* estimated size */

    avio_w8(pb, MAT_SIZE);

    avio_w8(pb, 4);

    avio_wb32(pb, avio_size(pb) / 1024);

    return updateSize(pb, pos);

}

static int gxf_write_track_description_section(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos;

    int i;

    pos = avio_tell(pb);

    avio_wb16(pb, 0); /* size */

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

        gxf_write_track_description(s, s->streams[i]->priv_data, i);

    gxf_write_track_description(s, &gxf->timecode_track, s->nb_streams);

    return updateSize(pb, pos);

}

static int gxf_write_map_packet(AVFormatContext *s, int rewrite)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos = avio_tell(pb);

    if (!rewrite) {

        if (!(gxf->map_offsets_nb % 30)) {

            gxf->map_offsets = av_realloc(gxf->map_offsets,

                                          (gxf->map_offsets_nb+30)*sizeof(*gxf->map_offsets));

            if (!gxf->map_offsets) {

                av_log(s, AV_LOG_ERROR, "could not realloc map offsets\n");

                return -1;

            }

        }

        gxf->map_offsets[gxf->map_offsets_nb++] = pos; // do not increment here

    }

    gxf_write_packet_header(pb, PKT_MAP);

    /* preamble */

    avio_w8(pb, 0xE0); /* version */

    avio_w8(pb, 0xFF); /* reserved */

    gxf_write_material_data_section(s);

    gxf_write_track_description_section(s);

    return updatePacketSize(pb, pos);

}

static int gxf_write_flt_packet(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos = avio_tell(pb);

    int fields_per_flt = (gxf->nb_fields+1) / 1000 + 1;

    int flt_entries = gxf->nb_fields / fields_per_flt;

    int i = 0;

    gxf_write_packet_header(pb, PKT_FLT);

    avio_wl32(pb, fields_per_flt); /* number of fields */

    avio_wl32(pb, flt_entries); /* number of active flt entries */

    if (gxf->flt_entries) {

        for (i = 0; i < flt_entries; i++)

            avio_wl32(pb, gxf->flt_entries[(i*fields_per_flt)>>1]);

    }

    for (; i < 1000; i++)

        avio_wl32(pb, 0);

    return updatePacketSize(pb, pos);

}

static int gxf_write_umf_material_description(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int timecode_base = gxf->time_base.den == 60000 ? 60 : 50;

    // XXX drop frame

    uint32_t timecode =

        gxf->nb_fields / (timecode_base * 3600) % 24 << 24 | // hours

        gxf->nb_fields / (timecode_base * 60) % 60   << 16 | // minutes

        gxf->nb_fields /  timecode_base % 60         <<  8 | // seconds

        gxf->nb_fields %  timecode_base;                     // fields

    avio_wl32(pb, gxf->flags);

    avio_wl32(pb, gxf->nb_fields); /* length of the longest track */

    avio_wl32(pb, gxf->nb_fields); /* length of the shortest track */

    avio_wl32(pb, 0); /* mark in */

    avio_wl32(pb, gxf->nb_fields); /* mark out */

    avio_wl32(pb, 0); /* timecode mark in */

    avio_wl32(pb, timecode); /* timecode mark out */

    avio_wl64(pb, s->timestamp); /* modification time */

    avio_wl64(pb, s->timestamp); /* creation time */

    avio_wl16(pb, 0); /* reserved */

    avio_wl16(pb, 0); /* reserved */

    avio_wl16(pb, gxf->audio_tracks);

    avio_wl16(pb, 1); /* timecode track count */

    avio_wl16(pb, 0); /* reserved */

    avio_wl16(pb, gxf->mpeg_tracks);

    return 48;

}

static int gxf_write_umf_payload(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    avio_wl32(pb, gxf->umf_length); /* total length of the umf data */

    avio_wl32(pb, 3); /* version */

    avio_wl32(pb, s->nb_streams+1);

    avio_wl32(pb, gxf->umf_track_offset); /* umf track section offset */

    avio_wl32(pb, gxf->umf_track_size);

    avio_wl32(pb, s->nb_streams+1);

    avio_wl32(pb, gxf->umf_media_offset);

    avio_wl32(pb, gxf->umf_media_size);

    avio_wl32(pb, gxf->umf_length); /* user data offset */

    avio_wl32(pb, 0); /* user data size */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    return 48;

}

static int gxf_write_umf_track_description(AVFormatContext *s)

{

    AVIOContext *pb = s->pb;

    GXFContext *gxf = s->priv_data;

    int64_t pos = avio_tell(pb);

    int i;

    gxf->umf_track_offset = pos - gxf->umf_start_offset;

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

        GXFStreamContext *sc = s->streams[i]->priv_data;

        avio_wl16(pb, sc->media_info);

        avio_wl16(pb, 1);

    }

    avio_wl16(pb, gxf->timecode_track.media_info);

    avio_wl16(pb, 1);

    return avio_tell(pb) - pos;

}

static int gxf_write_umf_media_mpeg(AVIOContext *pb, AVStream *st)

{

    GXFStreamContext *sc = st->priv_data;

    if (st->codec->pix_fmt == PIX_FMT_YUV422P)

        avio_wl32(pb, 2);

    else

        avio_wl32(pb, 1); /* default to 420 */

    avio_wl32(pb, sc->first_gop_closed == 1); /* closed = 1, open = 0, unknown = 255 */

    avio_wl32(pb, 3); /* top = 1, bottom = 2, frame = 3, unknown = 0 */

    avio_wl32(pb, 1); /* I picture per GOP */

    avio_wl32(pb, sc->p_per_gop);

    avio_wl32(pb, sc->b_per_i_or_p);

    if (st->codec->codec_id == CODEC_ID_MPEG2VIDEO)

        avio_wl32(pb, 2);

    else if (st->codec->codec_id == CODEC_ID_MPEG1VIDEO)

        avio_wl32(pb, 1);

    else

        avio_wl32(pb, 0);

    avio_wl32(pb, 0); /* reserved */

    return 32;

}

static int gxf_write_umf_media_timecode(AVIOContext *pb, GXFStreamContext *sc)

{

    avio_wl32(pb, 1); /* non drop frame */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    return 32;

}

static int gxf_write_umf_media_dv(AVIOContext *pb, GXFStreamContext *sc)

{

    int i;

    for (i = 0; i < 8; i++) {

        avio_wb32(pb, 0);

    }

    return 32;

}

static int gxf_write_umf_media_audio(AVIOContext *pb, GXFStreamContext *sc)

{

    avio_wl64(pb, av_dbl2int(1)); /* sound level to begin to */

    avio_wl64(pb, av_dbl2int(1)); /* sound level to begin to */

    avio_wl32(pb, 0); /* number of fields over which to ramp up sound level */

    avio_wl32(pb, 0); /* number of fields over which to ramp down sound level */

    avio_wl32(pb, 0); /* reserved */

    avio_wl32(pb, 0); /* reserved */

    return 32;

}

#if 0

static int gxf_write_umf_media_mjpeg(AVIOContext *pb, GXFStreamContext *sc)

{

    avio_wb64(pb, 0); /* FIXME FLOAT max chroma quant level */

    avio_wb64(pb, 0); /* FIXME FLOAT max luma quant level */

    avio_wb64(pb, 0); /* FIXME FLOAT min chroma quant level */

    avio_wb64(pb, 0); /* FIXME FLOAT min luma quant level */

    return 32;

}

#endif

static int gxf_write_umf_media_description(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos;

    int i, j;

    pos = avio_tell(pb);

    gxf->umf_media_offset = pos - gxf->umf_start_offset;

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

        GXFStreamContext *sc;

        int64_t startpos, curpos;

        if (i == s->nb_streams)

            sc = &gxf->timecode_track;

        else

            sc = s->streams[i]->priv_data;

        startpos = avio_tell(pb);

        avio_wl16(pb, 0); /* length */

        avio_wl16(pb, sc->media_info);

        avio_wl16(pb, 0); /* reserved */

        avio_wl16(pb, 0); /* reserved */

        avio_wl32(pb, gxf->nb_fields);

        avio_wl32(pb, 0); /* attributes rw, ro */

        avio_wl32(pb, 0); /* mark in */

        avio_wl32(pb, gxf->nb_fields); /* mark out */

        avio_write(pb, ES_NAME_PATTERN, strlen(ES_NAME_PATTERN));

        avio_wb16(pb, sc->media_info);

        for (j = strlen(ES_NAME_PATTERN)+2; j < 88; j++)

            avio_w8(pb, 0);

        avio_wl32(pb, sc->track_type);

        avio_wl32(pb, sc->sample_rate);

        avio_wl32(pb, sc->sample_size);

        avio_wl32(pb, 0); /* reserved */

        if (sc == &gxf->timecode_track)

            gxf_write_umf_media_timecode(pb, sc); /* 8 0bytes */

        else {

            AVStream *st = s->streams[i];

            switch (st->codec->codec_id) {

            case CODEC_ID_MPEG1VIDEO:

            case CODEC_ID_MPEG2VIDEO:

                gxf_write_umf_media_mpeg(pb, st);

                break;

            case CODEC_ID_PCM_S16LE:

                gxf_write_umf_media_audio(pb, sc);

                break;

            case CODEC_ID_DVVIDEO:

                gxf_write_umf_media_dv(pb, sc);

                break;

            }

        }

        curpos = avio_tell(pb);

        avio_seek(pb, startpos, SEEK_SET);

        avio_wl16(pb, curpos - startpos);

        avio_seek(pb, curpos, SEEK_SET);

    }

    return avio_tell(pb) - pos;

}

static int gxf_write_umf_packet(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t pos = avio_tell(pb);

    gxf_write_packet_header(pb, PKT_UMF);

    /* preamble */

    avio_w8(pb, 3); /* first and last (only) packet */

    avio_wb32(pb, gxf->umf_length); /* data length */

    gxf->umf_start_offset = avio_tell(pb);

    gxf_write_umf_payload(s);

    gxf_write_umf_material_description(s);

    gxf->umf_track_size = gxf_write_umf_track_description(s);

    gxf->umf_media_size = gxf_write_umf_media_description(s);

    gxf->umf_length = avio_tell(pb) - gxf->umf_start_offset;

    return updatePacketSize(pb, pos);

}

static const int GXF_samples_per_frame[] = { 32768, 0 };

static void gxf_init_timecode_track(GXFStreamContext *sc, GXFStreamContext *vsc)

{

    if (!vsc)

        return;

    sc->media_type = vsc->sample_rate == 60 ? 7 : 8;

    sc->sample_rate = vsc->sample_rate;

    sc->media_info = ('T'<<8) | '0';

    sc->track_type = 3;

    sc->frame_rate_index = vsc->frame_rate_index;

    sc->lines_index = vsc->lines_index;

    sc->sample_size = 16;

    sc->fields = vsc->fields;

}

static int gxf_write_header(AVFormatContext *s)

{

    AVIOContext *pb = s->pb;

    GXFContext *gxf = s->priv_data;

    GXFStreamContext *vsc = NULL;

    uint8_t tracks[255] = {0};

    int i, media_info = 0;

    if (!pb->seekable) {

        av_log(s, AV_LOG_ERROR, "gxf muxer does not support streamed output, patch welcome");

        return -1;

    }

    gxf->flags |= 0x00080000; /* material is simple clip */

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

        AVStream *st = s->streams[i];

        GXFStreamContext *sc = av_mallocz(sizeof(*sc));

        if (!sc)

            return AVERROR(ENOMEM);

        st->priv_data = sc;

        sc->media_type = ff_codec_get_tag(gxf_media_types, st->codec->codec_id);

        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {

            if (st->codec->codec_id != CODEC_ID_PCM_S16LE) {

                av_log(s, AV_LOG_ERROR, "only 16 BIT PCM LE allowed for now\n");

                return -1;

            }

            if (st->codec->sample_rate != 48000) {

                av_log(s, AV_LOG_ERROR, "only 48000hz sampling rate is allowed\n");

                return -1;

            }

            if (st->codec->channels != 1) {

                av_log(s, AV_LOG_ERROR, "only mono tracks are allowed\n");

                return -1;

            }

            sc->track_type = 2;

            sc->sample_rate = st->codec->sample_rate;

            av_set_pts_info(st, 64, 1, sc->sample_rate);

            sc->sample_size = 16;

            sc->frame_rate_index = -2;

            sc->lines_index = -2;

            sc->fields = -2;

            gxf->audio_tracks++;

            gxf->flags |= 0x04000000; /* audio is 16 bit pcm */

            media_info = 'A';

        } else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

            if (i != 0) {

                av_log(s, AV_LOG_ERROR, "video stream must be the first track\n");

                return -1;

            }

            /* FIXME check from time_base ? */

            if (st->codec->height == 480 || st->codec->height == 512) { /* NTSC or NTSC+VBI */

                sc->frame_rate_index = 5;

                sc->sample_rate = 60;

                gxf->flags |= 0x00000080;

                gxf->time_base = (AVRational){ 1001, 60000 };

            } else if (st->codec->height == 576 || st->codec->height == 608) { /* PAL or PAL+VBI */

                sc->frame_rate_index = 6;

                sc->media_type++;

                sc->sample_rate = 50;

                gxf->flags |= 0x00000040;

                gxf->time_base = (AVRational){ 1, 50 };

            } else {

                av_log(s, AV_LOG_ERROR, "unsupported video resolution, "

                       "gxf muxer only accepts PAL or NTSC resolutions currently\n");

                return -1;

            }

            av_set_pts_info(st, 64, gxf->time_base.num, gxf->time_base.den);

            if (gxf_find_lines_index(st) < 0)

                sc->lines_index = -1;

            sc->sample_size = st->codec->bit_rate;

            sc->fields = 2; /* interlaced */

            vsc = sc;

            switch (st->codec->codec_id) {

            case CODEC_ID_MJPEG:

                sc->track_type = 1;

                gxf->flags |= 0x00004000;

                media_info = 'J';

                break;

            case CODEC_ID_MPEG1VIDEO:

                sc->track_type = 9;

                gxf->mpeg_tracks++;

                media_info = 'L';

                break;

            case CODEC_ID_MPEG2VIDEO:

                sc->first_gop_closed = -1;

                sc->track_type = 4;

                gxf->mpeg_tracks++;

                gxf->flags |= 0x00008000;

                media_info = 'M';

                break;

            case CODEC_ID_DVVIDEO:

                if (st->codec->pix_fmt == PIX_FMT_YUV422P) {

                    sc->media_type += 2;

                    sc->track_type = 6;

                    gxf->flags |= 0x00002000;

                    media_info = 'E';

                } else {

                    sc->track_type = 5;

                    gxf->flags |= 0x00001000;

                    media_info = 'D';

                }

                break;

            default:

                av_log(s, AV_LOG_ERROR, "video codec not supported\n");

                return -1;

            }

        }

        /* FIXME first 10 audio tracks are 0 to 9 next 22 are A to V */

        sc->media_info = media_info<<8 | ('0'+tracks[media_info]++);

        sc->order = s->nb_streams - st->index;

    }

    if (ff_audio_interleave_init(s, GXF_samples_per_frame, (AVRational){ 1, 48000 }) < 0)

        return -1;

    gxf_init_timecode_track(&gxf->timecode_track, vsc);

    gxf->flags |= 0x200000; // time code track is non-drop frame

    gxf_write_map_packet(s, 0);

    gxf_write_flt_packet(s);

    gxf_write_umf_packet(s);

    gxf->packet_count = 3;

    avio_flush(pb);

    return 0;

}

static int gxf_write_eos_packet(AVIOContext *pb)

{

    int64_t pos = avio_tell(pb);

    gxf_write_packet_header(pb, PKT_EOS);

    return updatePacketSize(pb, pos);

}

static int gxf_write_trailer(AVFormatContext *s)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t end;

    int i;

    ff_audio_interleave_close(s);

    gxf_write_eos_packet(pb);

    end = avio_tell(pb);

    avio_seek(pb, 0, SEEK_SET);

    /* overwrite map, flt and umf packets with new values */

    gxf_write_map_packet(s, 1);

    gxf_write_flt_packet(s);

    gxf_write_umf_packet(s);

    avio_flush(pb);

    /* update duration in all map packets */

    for (i = 1; i < gxf->map_offsets_nb; i++) {

        avio_seek(pb, gxf->map_offsets[i], SEEK_SET);

        gxf_write_map_packet(s, 1);

        avio_flush(pb);

    }

    avio_seek(pb, end, SEEK_SET);

    av_freep(&gxf->flt_entries);

    av_freep(&gxf->map_offsets);

    return 0;

}

static int gxf_parse_mpeg_frame(GXFStreamContext *sc, const uint8_t *buf, int size)

{

    uint32_t c=-1;

    int i;

    for(i=0; i<size-4 && c!=0x100; i++){

        c = (c<<8) + buf[i];

        if(c == 0x1B8 && sc->first_gop_closed == -1) /* GOP start code */

            sc->first_gop_closed= (buf[i+4]>>6)&1;

    }

    return (buf[i+1]>>3)&7;

}

static int gxf_write_media_preamble(AVFormatContext *s, AVPacket *pkt, int size)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st = s->streams[pkt->stream_index];

    GXFStreamContext *sc = st->priv_data;

    unsigned field_nb;

    /* If the video is frame-encoded, the frame numbers shall be represented by

     * even field numbers.

     * see SMPTE360M-2004  6.4.2.1.3 Media field number */

    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

        field_nb = gxf->nb_fields;

    } else {

        field_nb = av_rescale_rnd(pkt->dts, gxf->time_base.den,

                                  (int64_t)48000*gxf->time_base.num, AV_ROUND_UP);

    }

    avio_w8(pb, sc->media_type);

    avio_w8(pb, st->index);

    avio_wb32(pb, field_nb);

    if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {

        avio_wb16(pb, 0);

        avio_wb16(pb, size / 2);

    } else if (st->codec->codec_id == CODEC_ID_MPEG2VIDEO) {

        int frame_type = gxf_parse_mpeg_frame(sc, pkt->data, pkt->size);

        if (frame_type == AV_PICTURE_TYPE_I) {

            avio_w8(pb, 0x0d);

            sc->iframes++;

        } else if (frame_type == AV_PICTURE_TYPE_B) {

            avio_w8(pb, 0x0f);

            sc->bframes++;

        } else {

            avio_w8(pb, 0x0e);

            sc->pframes++;

        }

        avio_wb24(pb, size);

    } else if (st->codec->codec_id == CODEC_ID_DVVIDEO) {

        avio_w8(pb, size / 4096);

        avio_wb24(pb, 0);

    } else

        avio_wb32(pb, size);

    avio_wb32(pb, field_nb);

    avio_w8(pb, 1); /* flags */

    avio_w8(pb, 0); /* reserved */

    return 16;

}

static int gxf_write_packet(AVFormatContext *s, AVPacket *pkt)

{

    GXFContext *gxf = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st = s->streams[pkt->stream_index];

    int64_t pos = avio_tell(pb);

    int padding = 0;

    int packet_start_offset = avio_tell(pb) / 1024;

    gxf_write_packet_header(pb, PKT_MEDIA);

    if (st->codec->codec_id == CODEC_ID_MPEG2VIDEO && pkt->size % 4) /* MPEG-2 frames must be padded */

        padding = 4 - pkt->size % 4;

    else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO)

        padding = GXF_AUDIO_PACKET_SIZE - pkt->size;

    gxf_write_media_preamble(s, pkt, pkt->size + padding);

    avio_write(pb, pkt->data, pkt->size);

    gxf_write_padding(pb, padding);

    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

        if (!(gxf->flt_entries_nb % 500)) {

            gxf->flt_entries = av_realloc(gxf->flt_entries,

                                          (gxf->flt_entries_nb+500)*sizeof(*gxf->flt_entries));

            if (!gxf->flt_entries) {

                av_log(s, AV_LOG_ERROR, "could not reallocate flt entries\n");

                return -1;

            }

        }

        gxf->flt_entries[gxf->flt_entries_nb++] = packet_start_offset;

        gxf->nb_fields += 2; // count fields

    }

    updatePacketSize(pb, pos);

    gxf->packet_count++;

    if (gxf->packet_count == 100) {

        gxf_write_map_packet(s, 0);

        gxf->packet_count = 0;

    }

    avio_flush(pb);

    return 0;

}

static int gxf_compare_field_nb(AVFormatContext *s, AVPacket *next, AVPacket *cur)

{

    GXFContext *gxf = s->priv_data;

    AVPacket *pkt[2] = { cur, next };

    int i, field_nb[2];

    GXFStreamContext *sc[2];

    for (i = 0; i < 2; i++) {

        AVStream *st = s->streams[pkt[i]->stream_index];

        sc[i] = st->priv_data;

        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {

            field_nb[i] = av_rescale_rnd(pkt[i]->dts, gxf->time_base.den,

                                         (int64_t)48000*gxf->time_base.num, AV_ROUND_UP);

            field_nb[i] &= ~1; // compare against even field number because audio must be before video

        } else

            field_nb[i] = pkt[i]->dts; // dts are field based

    }

    return field_nb[1] > field_nb[0] ||

        (field_nb[1] == field_nb[0] && sc[1]->order > sc[0]->order);

}

static int gxf_interleave_packet(AVFormatContext *s, AVPacket *out, AVPacket *pkt, int flush)

{

    if (pkt && s->streams[pkt->stream_index]->codec->codec_type == AVMEDIA_TYPE_VIDEO)

        pkt->duration = 2; // enforce 2 fields

    return ff_audio_rechunk_interleave(s, out, pkt, flush,

                               av_interleave_packet_per_dts, gxf_compare_field_nb);

}

AVOutputFormat ff_gxf_muxer = {

    "gxf",

    NULL_IF_CONFIG_SMALL("GXF format"),

    NULL,

    "gxf",

    sizeof(GXFContext),

    CODEC_ID_PCM_S16LE,

    CODEC_ID_MPEG2VIDEO,

    gxf_write_header,

    gxf_write_packet,

    gxf_write_trailer,

    0,

    NULL,

    gxf_interleave_packet,

};