/*
  * 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 "libavutil/avassert.h"

 #include "libavutil/intfloat.h"

 #include "libavutil/opt.h"

 #include "libavutil/mathematics.h"

 #include "libavutil/timecode.h"

 #include "avformat.h"

 #include "internal.h"

 #include "gxf.h"

 #include "audiointerleave.h"

 
 #define GXF_AUDIO_PACKET_SIZE 65536
 

 #define GXF_TIMECODE(c, d, h, m, s, f) \
     ((c) << 30 | (d) << 29 | (h) << 24 | (m) << 16 | (s) << 8 | (f))
 
 typedef struct GXFTimecode{
     int hh;
     int mm;
     int ss;
     int ff;
     int color;
     int drop;
 } GXFTimecode;
 

 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 {

     AVClass *av_class;

     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;

     GXFTimecode tc;

 } 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[] = {

     { AV_CODEC_ID_MJPEG     ,   3 }, /* NTSC */
     { AV_CODEC_ID_MJPEG     ,   4 }, /* PAL */
     { AV_CODEC_ID_PCM_S24LE ,   9 },
     { AV_CODEC_ID_PCM_S16LE ,  10 },
     { AV_CODEC_ID_MPEG2VIDEO,  11 }, /* NTSC */
     { AV_CODEC_ID_MPEG2VIDEO,  12 }, /* PAL */
     { AV_CODEC_ID_DVVIDEO   ,  13 }, /* NTSC */
     { AV_CODEC_ID_DVVIDEO   ,  14 }, /* PAL */
     { AV_CODEC_ID_DVVIDEO   ,  15 }, /* 50M NTSC */
     { AV_CODEC_ID_DVVIDEO   ,  16 }, /* 50M PAL */
     { AV_CODEC_ID_AC3       ,  17 },
     //{ AV_CODEC_ID_NONE,  ,   18 }, /* Non compressed 24 bit audio */
     { AV_CODEC_ID_MPEG2VIDEO,  20 }, /* MPEG HD */
     { AV_CODEC_ID_MPEG1VIDEO,  22 }, /* NTSC */
     { AV_CODEC_ID_MPEG1VIDEO,  23 }, /* PAL */
     { AV_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, sizeof(buffer), "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 == AV_PIX_FMT_YUV422P ? 2 : 1, sc->first_gop_closed == 1,

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

     av_assert0(size < sizeof(buffer));

     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_dv_auxiliary(AVIOContext *pb, AVStream *st)
 {
     int64_t track_aux_data = 0;
 
     avio_w8(pb, TRACK_AUX);
     avio_w8(pb, 8);

     if (st->codec->pix_fmt == AV_PIX_FMT_YUV420P)

         track_aux_data |= 0x01;     /* marks stream as DVCAM instead of DVPRO */
     track_aux_data |= 0x40000000;   /* aux data is valid */
     avio_wl64(pb, track_aux_data);
     return 8;
 }
 

 static int gxf_write_timecode_auxiliary(AVIOContext *pb, GXFContext *gxf)

 {

     uint32_t timecode = GXF_TIMECODE(gxf->tc.color, gxf->tc.drop,
                                      gxf->tc.hh, gxf->tc.mm,
                                      gxf->tc.ss, gxf->tc.ff);
 

     avio_w8(pb, TRACK_AUX);
     avio_w8(pb, 8);

     avio_wl32(pb, timecode);

     /* reserved */

     avio_wl32(pb, 0);

     return 8;
 }
 

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

 {

     GXFContext *gxf = s->priv_data;

     AVIOContext *pb = s->pb;

     int64_t pos;

 
     /* 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);

     switch (sc->track_type) {
         case 3:     /* timecode */

             gxf_write_timecode_auxiliary(pb, gxf);

             break;
         case 4:     /* MPEG2 */
         case 9:     /* MPEG1 */
             gxf_write_mpeg_auxiliary(pb, s->streams[index]);
             break;
         case 5:     /* DV25 */
         case 6:     /* DV50 */
             gxf_write_dv_auxiliary(pb, s->streams[index]);
             break;
         default:
             avio_w8(pb, TRACK_AUX);
             avio_w8(pb, 8);

             avio_wl64(pb, 0);

     }
 
     /* file system version */

     avio_w8(pb, TRACK_VER);
     avio_w8(pb, 4);
     avio_wb32(pb, 0);

 
     /* 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)) {

             int err;
             if ((err = av_reallocp_array(&gxf->map_offsets,
                                          gxf->map_offsets_nb + 30,
                                          sizeof(*gxf->map_offsets))) < 0) {
                 gxf->map_offsets_nb = 0;

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

                 return err;

             }
         }
         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;

     int64_t timestamp = 0;
     AVDictionaryEntry *t;

     uint64_t nb_fields;
     uint32_t timecode_in; // timecode at mark in
     uint32_t timecode_out; // timecode at mark out

     if (t = av_dict_get(s->metadata, "creation_time", NULL, 0))
         timestamp = ff_iso8601_to_unix_time(t->value);

     timecode_in = GXF_TIMECODE(gxf->tc.color, gxf->tc.drop,
                                gxf->tc.hh, gxf->tc.mm,
                                gxf->tc.ss, gxf->tc.ff);
 
     nb_fields = gxf->nb_fields +
                 gxf->tc.hh * (timecode_base * 3600) +
                 gxf->tc.mm * (timecode_base * 60)   +
                 gxf->tc.ss * timecode_base          +
                 gxf->tc.ff;
 
     timecode_out = GXF_TIMECODE(gxf->tc.color, gxf->tc.drop,
                                 nb_fields / (timecode_base * 3600) % 24,
                                 nb_fields / (timecode_base * 60)   % 60,
                                 nb_fields /  timecode_base % 60,
                                 nb_fields %  timecode_base);

     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, timecode_in); /* timecode mark in */
     avio_wl32(pb, timecode_out); /* timecode mark out */

     avio_wl64(pb, timestamp); /* modification time */
     avio_wl64(pb, 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 == AV_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 == AV_CODEC_ID_MPEG2VIDEO)

         avio_wl32(pb, 2);

     else if (st->codec->codec_id == AV_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, int drop)

 {

     avio_wl32(pb, drop); /* 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, AVStream *st)

 {

     int dv_umf_data = 0;

     if (st->codec->pix_fmt == AV_PIX_FMT_YUV420P)

         dv_umf_data |= 0x20; /* marks as DVCAM instead of DVPRO */
     avio_wl32(pb, dv_umf_data);
     avio_wl32(pb, 0);
     avio_wl32(pb, 0);
     avio_wl32(pb, 0);
     avio_wl32(pb, 0);
     avio_wl32(pb, 0);
     avio_wl32(pb, 0);
     avio_wl32(pb, 0);

     return 32;
 }
 

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

 {

     avio_wl64(pb, av_double2int(1)); /* sound level to begin to */
     avio_wl64(pb, av_double2int(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;
 }
 

 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, gxf->tc.drop);

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

             switch (st->codec->codec_id) {

             case AV_CODEC_ID_MPEG1VIDEO:
             case AV_CODEC_ID_MPEG2VIDEO:

                 gxf_write_umf_media_mpeg(pb, st);
                 break;

             case AV_CODEC_ID_PCM_S16LE:

                 gxf_write_umf_media_audio(pb, sc);
                 break;

             case AV_CODEC_ID_DVVIDEO:

                 gxf_write_umf_media_dv(pb, sc, st);

                 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_init_timecode(AVFormatContext *s, GXFTimecode *tc, const char *tcstr, int fields)

 {
     char c;
 

     if (sscanf(tcstr, "%d:%d:%d%c%d", &tc->hh, &tc->mm, &tc->ss, &c, &tc->ff) != 5) {

         av_log(s, AV_LOG_ERROR, "unable to parse timecode, "
                                 "syntax: hh:mm:ss[:;.]ff\n");
         return -1;
     }
 
     tc->color = 0;
     tc->drop = c != ':';
 
     if (fields == 2)
         tc->ff = tc->ff * 2;
 
     return 0;
 }
 

 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;

     int ret;

     AVDictionaryEntry *tcr = av_dict_get(s->metadata, "timecode", NULL, 0);

     if (!pb->seekable) {

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

         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 != AV_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;

             avpriv_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;

             }

             if (!tcr)
                 tcr = av_dict_get(st->metadata, "timecode", NULL, 0);

             avpriv_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 AV_CODEC_ID_MJPEG:

                 sc->track_type = 1;
                 gxf->flags |= 0x00004000;
                 media_info = 'J';
                 break;

             case AV_CODEC_ID_MPEG1VIDEO:

                 sc->track_type = 9;
                 gxf->mpeg_tracks++;
                 media_info = 'L';
                 break;

             case AV_CODEC_ID_MPEG2VIDEO:

                 sc->first_gop_closed = -1;

                 sc->track_type = 4;
                 gxf->mpeg_tracks++;
                 gxf->flags |= 0x00008000;

                 media_info = 'M';

                 break;

             case AV_CODEC_ID_DVVIDEO:

                 if (st->codec->pix_fmt == AV_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;
 

     if (tcr && vsc)

         gxf_init_timecode(s, &gxf->tc, tcr->value, vsc->fields);

     gxf_init_timecode_track(&gxf->timecode_track, vsc);
     gxf->flags |= 0x200000; // time code track is non-drop frame
 

     if ((ret = gxf_write_map_packet(s, 0)) < 0)
         return ret;

     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;

     int ret;

     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 */

     if ((ret = gxf_write_map_packet(s, 1)) < 0)
         return ret;

     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);

         if ((ret = gxf_write_map_packet(s, 1)) < 0)
             return ret;

         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 == AV_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 == AV_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;

     int ret;

 
     gxf_write_packet_header(pb, PKT_MEDIA);

     if (st->codec->codec_id == AV_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)) {

             int err;
             if ((err = av_reallocp_array(&gxf->flt_entries,
                                          gxf->flt_entries_nb + 500,
                                          sizeof(*gxf->flt_entries))) < 0) {
                 gxf->flt_entries_nb = 0;

                 gxf->nb_fields = 0;

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

                 return err;

             }
         }

         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) {

         if ((ret = gxf_write_map_packet(s, 0)) < 0)
             return ret;

         gxf->packet_count = 0;
     }
 
     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,

                                ff_interleave_packet_per_dts, gxf_compare_field_nb);

 }
 

 AVOutputFormat ff_gxf_muxer = {

     .name              = "gxf",

     .long_name         = NULL_IF_CONFIG_SMALL("GXF (General eXchange Format)"),

     .extensions        = "gxf",
     .priv_data_size    = sizeof(GXFContext),

     .audio_codec       = AV_CODEC_ID_PCM_S16LE,
     .video_codec       = AV_CODEC_ID_MPEG2VIDEO,

     .write_header      = gxf_write_header,
     .write_packet      = gxf_write_packet,
     .write_trailer     = gxf_write_trailer,
     .interleave_packet = gxf_interleave_packet,

 };