/*
  * "Real" compatible muxer.

  * Copyright (c) 2000, 2001 Fabrice Bellard

  *
  * 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 "avio_internal.h"

 #include "rm.h"

 #include "libavutil/dict.h"

 typedef struct {
     int nb_packets;
     int packet_total_size;
     int packet_max_size;
     /* codec related output */
     int bit_rate;
     float frame_rate;
     int nb_frames;    /* current frame number */
     int total_frames; /* total number of frames */
     int num;
     AVCodecContext *enc;
 } StreamInfo;
 
 typedef struct {
     StreamInfo streams[2];
     StreamInfo *audio_stream, *video_stream;
     int data_pos; /* position of the data after the header */
 } RMMuxContext;
 

 /* in ms */
 #define BUFFER_DURATION 0
 
 

 static void put_str(AVIOContext *s, const char *tag)

 {

     avio_wb16(s,strlen(tag));

     while (*tag) {

         avio_w8(s, *tag++);

     }
 }
 

 static void put_str8(AVIOContext *s, const char *tag)

 {

     avio_w8(s, strlen(tag));

     while (*tag) {

         avio_w8(s, *tag++);

     }
 }
 

 static int rv10_write_header(AVFormatContext *ctx,

                              int data_size, int index_pos)

 {

     RMMuxContext *rm = ctx->priv_data;

     AVIOContext *s = ctx->pb;

     StreamInfo *stream;
     unsigned char *data_offset_ptr, *start_ptr;
     const char *desc, *mimetype;
     int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
     int bit_rate, v, duration, flags, data_pos;

     AVDictionaryEntry *tag;

 
     start_ptr = s->buf_ptr;
 

     ffio_wfourcc(s, ".RMF");

     avio_wb32(s,18); /* header size */
     avio_wb16(s,0);
     avio_wb32(s,0);
     avio_wb32(s,4 + ctx->nb_streams); /* num headers */

     ffio_wfourcc(s,"PROP");

     avio_wb32(s, 50);
     avio_wb16(s, 0);

     packet_max_size = 0;
     packet_total_size = 0;
     nb_packets = 0;
     bit_rate = 0;
     duration = 0;
     for(i=0;i<ctx->nb_streams;i++) {
         StreamInfo *stream = &rm->streams[i];
         bit_rate += stream->bit_rate;
         if (stream->packet_max_size > packet_max_size)
             packet_max_size = stream->packet_max_size;
         nb_packets += stream->nb_packets;
         packet_total_size += stream->packet_total_size;
         /* select maximum duration */
         v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
         if (v > duration)
             duration = v;
     }

     avio_wb32(s, bit_rate); /* max bit rate */
     avio_wb32(s, bit_rate); /* avg bit rate */
     avio_wb32(s, packet_max_size);        /* max packet size */

     if (nb_packets > 0)
         packet_avg_size = packet_total_size / nb_packets;
     else
         packet_avg_size = 0;

     avio_wb32(s, packet_avg_size);        /* avg packet size */
     avio_wb32(s, nb_packets);  /* num packets */
     avio_wb32(s, duration); /* duration */
     avio_wb32(s, BUFFER_DURATION);           /* preroll */
     avio_wb32(s, index_pos);           /* index offset */

     /* computation of data the data offset */
     data_offset_ptr = s->buf_ptr;

     avio_wb32(s, 0);           /* data offset : will be patched after */
     avio_wb16(s, ctx->nb_streams);    /* num streams */

     flags = 1 | 2; /* save allowed & perfect play */

     if (!s->seekable)

         flags |= 4; /* live broadcast */

     avio_wb16(s, flags);

 
     /* comments */
 

     ffio_wfourcc(s,"CONT");

     size =  4 * 2 + 10;
     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {

         tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);

         if(tag) size += strlen(tag->value);
     }

     avio_wb32(s,size);
     avio_wb16(s,0);

     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {

         tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);

         put_str(s, tag ? tag->value : "");
     }

 
     for(i=0;i<ctx->nb_streams;i++) {
         int codec_data_size;
 
         stream = &rm->streams[i];
 

         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {

             desc = "The Audio Stream";
             mimetype = "audio/x-pn-realaudio";
             codec_data_size = 73;
         } else {
             desc = "The Video Stream";
             mimetype = "video/x-pn-realvideo";
             codec_data_size = 34;
         }
 

         ffio_wfourcc(s,"MDPR");

         size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;

         avio_wb32(s, size);
         avio_wb16(s, 0);

         avio_wb16(s, i); /* stream number */
         avio_wb32(s, stream->bit_rate); /* max bit rate */
         avio_wb32(s, stream->bit_rate); /* avg bit rate */
         avio_wb32(s, stream->packet_max_size);        /* max packet size */

         if (stream->nb_packets > 0)
             packet_avg_size = stream->packet_total_size /
                 stream->nb_packets;
         else
             packet_avg_size = 0;

         avio_wb32(s, packet_avg_size);        /* avg packet size */
         avio_wb32(s, 0);           /* start time */
         avio_wb32(s, BUFFER_DURATION);           /* preroll */

         /* duration */

         if (!s->seekable || !stream->total_frames)

             avio_wb32(s, (int)(3600 * 1000));

         else

             avio_wb32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));

         put_str8(s, desc);
         put_str8(s, mimetype);

         avio_wb32(s, codec_data_size);

         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {

             int coded_frame_size, fscode, sample_rate;
             sample_rate = stream->enc->sample_rate;
             coded_frame_size = (stream->enc->bit_rate *
                                 stream->enc->frame_size) / (8 * sample_rate);
             /* audio codec info */

             avio_write(s, ".ra", 3);

             avio_w8(s, 0xfd);
             avio_wb32(s, 0x00040000); /* version */

             ffio_wfourcc(s, ".ra4");

             avio_wb32(s, 0x01b53530); /* stream length */
             avio_wb16(s, 4); /* unknown */
             avio_wb32(s, 0x39); /* header size */

 
             switch(sample_rate) {
             case 48000:
             case 24000:
             case 12000:
                 fscode = 1;
                 break;
             default:
             case 44100:
             case 22050:
             case 11025:
                 fscode = 2;
                 break;
             case 32000:
             case 16000:
             case 8000:
                 fscode = 3;
             }

             avio_wb16(s, fscode); /* codec additional info, for AC-3, seems

                                      to be a frequency code */
             /* special hack to compensate rounding errors... */
             if (coded_frame_size == 557)
                 coded_frame_size--;

             avio_wb32(s, coded_frame_size); /* frame length */
             avio_wb32(s, 0x51540); /* unknown */

             avio_wb32(s, stream->enc->bit_rate / 8 * 60); /* bytes per minute */
             avio_wb32(s, stream->enc->bit_rate / 8 * 60); /* bytes per minute */

             avio_wb16(s, 0x01);

             /* frame length : seems to be very important */

             avio_wb16(s, coded_frame_size);
             avio_wb32(s, 0); /* unknown */
             avio_wb16(s, stream->enc->sample_rate); /* sample rate */
             avio_wb32(s, 0x10); /* unknown */
             avio_wb16(s, stream->enc->channels);

             put_str8(s, "Int0"); /* codec name */

             if (stream->enc->codec_tag) {

                 avio_w8(s, 4); /* tag length */
                 avio_wl32(s, stream->enc->codec_tag);

             } else {
                 av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
                 return -1;
             }

             avio_wb16(s, 0); /* title length */
             avio_wb16(s, 0); /* author length */
             avio_wb16(s, 0); /* copyright length */
             avio_w8(s, 0); /* end of header */

         } else {
             /* video codec info */

             avio_wb32(s,34); /* size */

             ffio_wfourcc(s, "VIDO");

             if(stream->enc->codec_id == AV_CODEC_ID_RV10)

                 ffio_wfourcc(s,"RV10");

             else

                 ffio_wfourcc(s,"RV20");

             avio_wb16(s, stream->enc->width);
             avio_wb16(s, stream->enc->height);
             avio_wb16(s, (int) stream->frame_rate); /* frames per seconds ? */
             avio_wb32(s,0);     /* unknown meaning */
             avio_wb16(s, (int) stream->frame_rate);  /* unknown meaning */
             avio_wb32(s,0);     /* unknown meaning */
             avio_wb16(s, 8);    /* unknown meaning */

             /* Seems to be the codec version: only use basic H263. The next
                versions seems to add a diffential DC coding as in
                MPEG... nothing new under the sun */

             if(stream->enc->codec_id == AV_CODEC_ID_RV10)

                 avio_wb32(s,0x10000000);

             else

                 avio_wb32(s,0x20103001);
             //avio_wb32(s,0x10003000);

         }
     }
 
     /* patch data offset field */
     data_pos = s->buf_ptr - start_ptr;
     rm->data_pos = data_pos;
     data_offset_ptr[0] = data_pos >> 24;
     data_offset_ptr[1] = data_pos >> 16;
     data_offset_ptr[2] = data_pos >> 8;
     data_offset_ptr[3] = data_pos;
 
     /* data stream */

     ffio_wfourcc(s, "DATA");

     avio_wb32(s,data_size + 10 + 8);
     avio_wb16(s,0);

     avio_wb32(s, nb_packets); /* number of packets */
     avio_wb32(s,0); /* next data header */

     return 0;

 }
 
 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
                                 int length, int key_frame)
 {
     int timestamp;

     AVIOContext *s = ctx->pb;

 
     stream->nb_packets++;
     stream->packet_total_size += length;
     if (length > stream->packet_max_size)
         stream->packet_max_size =  length;
 

     avio_wb16(s,0); /* version */
     avio_wb16(s,length + 12);
     avio_wb16(s, stream->num); /* stream number */

     timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;

     avio_wb32(s, timestamp); /* timestamp */
     avio_w8(s, 0); /* reserved */
     avio_w8(s, key_frame ? 2 : 0); /* flags */

 }
 
 static int rm_write_header(AVFormatContext *s)
 {

     RMMuxContext *rm = s->priv_data;

     StreamInfo *stream;
     int n;
     AVCodecContext *codec;
 

     if (s->nb_streams > 2) {
         av_log(s, AV_LOG_ERROR, "At most 2 streams are currently supported for muxing in RM\n");
         return AVERROR_PATCHWELCOME;
     }
 

     for(n=0;n<s->nb_streams;n++) {
         s->streams[n]->id = n;
         codec = s->streams[n]->codec;
         stream = &rm->streams[n];
         memset(stream, 0, sizeof(StreamInfo));
         stream->num = n;
         stream->bit_rate = codec->bit_rate;
         stream->enc = codec;
 
         switch(codec->codec_type) {

         case AVMEDIA_TYPE_AUDIO:

             rm->audio_stream = stream;
             stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;
             /* XXX: dummy values */
             stream->packet_max_size = 1024;
             stream->nb_packets = 0;
             stream->total_frames = stream->nb_packets;
             break;

         case AVMEDIA_TYPE_VIDEO:

             rm->video_stream = stream;
             stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num;
             /* XXX: dummy values */
             stream->packet_max_size = 4096;
             stream->nb_packets = 0;
             stream->total_frames = stream->nb_packets;
             break;
         default:
             return -1;
         }
     }
 

     if (rv10_write_header(s, 0, 0))
         return AVERROR_INVALIDDATA;

     avio_flush(s->pb);

     return 0;
 }
 
 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
 {
     uint8_t *buf1;

     RMMuxContext *rm = s->priv_data;

     AVIOContext *pb = s->pb;

     StreamInfo *stream = rm->audio_stream;
     int i;
 
     /* XXX: suppress this malloc */

     buf1 = av_malloc(size * sizeof(uint8_t));

     write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));

     if (stream->enc->codec_id == AV_CODEC_ID_AC3) {

         /* for AC-3, the words seem to be reversed */
         for(i=0;i<size;i+=2) {
             buf1[i] = buf[i+1];
             buf1[i+1] = buf[i];
         }

         avio_write(pb, buf1, size);

     } else {

         avio_write(pb, buf, size);

     }

     stream->nb_frames++;
     av_free(buf1);
     return 0;
 }
 
 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
 {

     RMMuxContext *rm = s->priv_data;

     AVIOContext *pb = s->pb;

     StreamInfo *stream = rm->video_stream;

     int key_frame = !!(flags & AV_PKT_FLAG_KEY);

 
     /* XXX: this is incorrect: should be a parameter */
 
     /* Well, I spent some time finding the meaning of these bits. I am
        not sure I understood everything, but it works !! */
 #if 1

     write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);

     /* bit 7: '1' if final packet of a frame converted in several packets */

     avio_w8(pb, 0x81);

     /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
        frame starting from 1 */
     if (key_frame) {

         avio_w8(pb, 0x81);

     } else {

         avio_w8(pb, 0x01);

     }

     if(size >= 0x4000){

         avio_wb32(pb, size); /* total frame size */
         avio_wb32(pb, size); /* offset from the start or the end */

     }else{

         avio_wb16(pb, 0x4000 | size); /* total frame size */
         avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */

     }

 #else
     /* full frame */
     write_packet_header(s, size + 6);

     avio_w8(pb, 0xc0);
     avio_wb16(pb, 0x4000 + size); /* total frame size */
     avio_wb16(pb, 0x4000 + packet_number * 126); /* position in stream */

 #endif

     avio_w8(pb, stream->nb_frames & 0xff);

     avio_write(pb, buf, size);

 
     stream->nb_frames++;
     return 0;
 }
 
 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     if (s->streams[pkt->stream_index]->codec->codec_type ==

         AVMEDIA_TYPE_AUDIO)

         return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
     else
         return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
 }
 
 static int rm_write_trailer(AVFormatContext *s)
 {

     RMMuxContext *rm = s->priv_data;

     int data_size, index_pos, i;

     AVIOContext *pb = s->pb;

     if (s->pb->seekable) {

         /* end of file: finish to write header */

         index_pos = avio_tell(pb);

         data_size = index_pos - rm->data_pos;
 

         /* FIXME: write index */
 

         /* undocumented end header */

         avio_wb32(pb, 0);
         avio_wb32(pb, 0);

         avio_seek(pb, 0, SEEK_SET);

         for(i=0;i<s->nb_streams;i++)
             rm->streams[i].total_frames = rm->streams[i].nb_frames;

         rv10_write_header(s, data_size, 0);

     } else {
         /* undocumented end header */

         avio_wb32(pb, 0);
         avio_wb32(pb, 0);

     }

     return 0;
 }
 
 

 AVOutputFormat ff_rm_muxer = {

     .name              = "rm",

     .long_name         = NULL_IF_CONFIG_SMALL("RealMedia"),

     .mime_type         = "application/vnd.rn-realmedia",
     .extensions        = "rm,ra",
     .priv_data_size    = sizeof(RMMuxContext),

     .audio_codec       = AV_CODEC_ID_AC3,
     .video_codec       = AV_CODEC_ID_RV10,

     .write_header      = rm_write_header,
     .write_packet      = rm_write_packet,
     .write_trailer     = rm_write_trailer,

     .codec_tag         = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },

 };