/*

  * ASF 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 "internal.h"

 #include "riff.h"

 #include "asf.h"

 #include "avio_internal.h"

 #include "libavutil/dict.h"

 
 #undef NDEBUG
 #include <assert.h>
 

 #define ASF_INDEXED_INTERVAL    10000000

 #define ASF_INDEX_BLOCK         (1<<9)

 #define ASF_PACKET_ERROR_CORRECTION_DATA_SIZE 0x2
 #define ASF_PACKET_ERROR_CORRECTION_FLAGS (\

                 ASF_PACKET_FLAG_ERROR_CORRECTION_PRESENT | \
                 ASF_PACKET_ERROR_CORRECTION_DATA_SIZE\
                 )

 
 #if (ASF_PACKET_ERROR_CORRECTION_FLAGS != 0)
 #   define ASF_PACKET_ERROR_CORRECTION_FLAGS_FIELD_SIZE 1
 #else
 #   define ASF_PACKET_ERROR_CORRECTION_FLAGS_FIELD_SIZE 0
 #endif
 
 #define ASF_PPI_PROPERTY_FLAGS (\

                 ASF_PL_FLAG_REPLICATED_DATA_LENGTH_FIELD_IS_BYTE | \
                 ASF_PL_FLAG_OFFSET_INTO_MEDIA_OBJECT_LENGTH_FIELD_IS_DWORD | \
                 ASF_PL_FLAG_MEDIA_OBJECT_NUMBER_LENGTH_FIELD_IS_BYTE | \
                 ASF_PL_FLAG_STREAM_NUMBER_LENGTH_FIELD_IS_BYTE \
                 )

 
 #define ASF_PPI_LENGTH_TYPE_FLAGS 0
 
 #define ASF_PAYLOAD_FLAGS ASF_PL_FLAG_PAYLOAD_LENGTH_FIELD_IS_WORD
 
 #if (ASF_PPI_FLAG_SEQUENCE_FIELD_IS_BYTE == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_SEQUENCE_FIELD_SIZE))
 #   define ASF_PPI_SEQUENCE_FIELD_SIZE 1
 #endif
 #if (ASF_PPI_FLAG_SEQUENCE_FIELD_IS_WORD == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_SEQUENCE_FIELD_SIZE))
 #   define ASF_PPI_SEQUENCE_FIELD_SIZE 2
 #endif
 #if (ASF_PPI_FLAG_SEQUENCE_FIELD_IS_DWORD == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_SEQUENCE_FIELD_SIZE))
 #   define ASF_PPI_SEQUENCE_FIELD_SIZE 4
 #endif
 #ifndef ASF_PPI_SEQUENCE_FIELD_SIZE
 #   define ASF_PPI_SEQUENCE_FIELD_SIZE 0
 #endif
 
 
 #if (ASF_PPI_FLAG_PACKET_LENGTH_FIELD_IS_BYTE == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_PACKET_LENGTH_FIELD_SIZE))
 #   define ASF_PPI_PACKET_LENGTH_FIELD_SIZE 1
 #endif
 #if (ASF_PPI_FLAG_PACKET_LENGTH_FIELD_IS_WORD == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_PACKET_LENGTH_FIELD_SIZE))
 #   define ASF_PPI_PACKET_LENGTH_FIELD_SIZE 2
 #endif
 #if (ASF_PPI_FLAG_PACKET_LENGTH_FIELD_IS_DWORD == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_PACKET_LENGTH_FIELD_SIZE))
 #   define ASF_PPI_PACKET_LENGTH_FIELD_SIZE 4
 #endif
 #ifndef ASF_PPI_PACKET_LENGTH_FIELD_SIZE
 #   define ASF_PPI_PACKET_LENGTH_FIELD_SIZE 0
 #endif
 
 #if (ASF_PPI_FLAG_PADDING_LENGTH_FIELD_IS_BYTE == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_PADDING_LENGTH_FIELD_SIZE))
 #   define ASF_PPI_PADDING_LENGTH_FIELD_SIZE 1
 #endif
 #if (ASF_PPI_FLAG_PADDING_LENGTH_FIELD_IS_WORD == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_PADDING_LENGTH_FIELD_SIZE))
 #   define ASF_PPI_PADDING_LENGTH_FIELD_SIZE 2
 #endif
 #if (ASF_PPI_FLAG_PADDING_LENGTH_FIELD_IS_DWORD == (ASF_PPI_LENGTH_TYPE_FLAGS & ASF_PPI_MASK_PADDING_LENGTH_FIELD_SIZE))
 #   define ASF_PPI_PADDING_LENGTH_FIELD_SIZE 4
 #endif
 #ifndef ASF_PPI_PADDING_LENGTH_FIELD_SIZE
 #   define ASF_PPI_PADDING_LENGTH_FIELD_SIZE 0
 #endif
 
 #if (ASF_PL_FLAG_REPLICATED_DATA_LENGTH_FIELD_IS_BYTE == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_REPLICATED_DATA_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_REPLICATED_DATA_LENGTH_FIELD_SIZE 1
 #endif
 #if (ASF_PL_FLAG_REPLICATED_DATA_LENGTH_FIELD_IS_WORD == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_REPLICATED_DATA_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_REPLICATED_DATA_LENGTH_FIELD_SIZE 2
 #endif
 #if (ASF_PL_FLAG_REPLICATED_DATA_LENGTH_FIELD_IS_DWORD == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_REPLICATED_DATA_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_REPLICATED_DATA_LENGTH_FIELD_SIZE 4
 #endif
 #ifndef ASF_PAYLOAD_REPLICATED_DATA_LENGTH_FIELD_SIZE
 #   define ASF_PAYLOAD_REPLICATED_DATA_LENGTH_FIELD_SIZE 0
 #endif
 
 #if (ASF_PL_FLAG_OFFSET_INTO_MEDIA_OBJECT_LENGTH_FIELD_IS_BYTE == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_OFFSET_INTO_MEDIA_OBJECT_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_OFFSET_INTO_MEDIA_OBJECT_FIELD_SIZE 1
 #endif
 #if (ASF_PL_FLAG_OFFSET_INTO_MEDIA_OBJECT_LENGTH_FIELD_IS_WORD == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_OFFSET_INTO_MEDIA_OBJECT_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_OFFSET_INTO_MEDIA_OBJECT_FIELD_SIZE 2
 #endif
 #if (ASF_PL_FLAG_OFFSET_INTO_MEDIA_OBJECT_LENGTH_FIELD_IS_DWORD == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_OFFSET_INTO_MEDIA_OBJECT_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_OFFSET_INTO_MEDIA_OBJECT_FIELD_SIZE 4
 #endif
 #ifndef ASF_PAYLOAD_OFFSET_INTO_MEDIA_OBJECT_FIELD_SIZE
 #   define ASF_PAYLOAD_OFFSET_INTO_MEDIA_OBJECT_FIELD_SIZE 0
 #endif
 
 #if (ASF_PL_FLAG_MEDIA_OBJECT_NUMBER_LENGTH_FIELD_IS_BYTE == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_MEDIA_OBJECT_NUMBER_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_MEDIA_OBJECT_NUMBER_FIELD_SIZE 1
 #endif
 #if (ASF_PL_FLAG_MEDIA_OBJECT_NUMBER_LENGTH_FIELD_IS_WORD == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_MEDIA_OBJECT_NUMBER_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_MEDIA_OBJECT_NUMBER_FIELD_SIZE 2
 #endif
 #if (ASF_PL_FLAG_MEDIA_OBJECT_NUMBER_LENGTH_FIELD_IS_DWORD == (ASF_PPI_PROPERTY_FLAGS & ASF_PL_MASK_MEDIA_OBJECT_NUMBER_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_MEDIA_OBJECT_NUMBER_FIELD_SIZE 4
 #endif
 #ifndef ASF_PAYLOAD_MEDIA_OBJECT_NUMBER_FIELD_SIZE
 #   define ASF_PAYLOAD_MEDIA_OBJECT_NUMBER_FIELD_SIZE 0
 #endif
 
 #if (ASF_PL_FLAG_PAYLOAD_LENGTH_FIELD_IS_BYTE == (ASF_PAYLOAD_FLAGS & ASF_PL_MASK_PAYLOAD_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_LENGTH_FIELD_SIZE 1
 #endif
 #if (ASF_PL_FLAG_PAYLOAD_LENGTH_FIELD_IS_WORD == (ASF_PAYLOAD_FLAGS & ASF_PL_MASK_PAYLOAD_LENGTH_FIELD_SIZE))
 #   define ASF_PAYLOAD_LENGTH_FIELD_SIZE 2
 #endif
 #ifndef ASF_PAYLOAD_LENGTH_FIELD_SIZE
 #   define ASF_PAYLOAD_LENGTH_FIELD_SIZE 0
 #endif
 
 #define PACKET_HEADER_MIN_SIZE (\

                 ASF_PACKET_ERROR_CORRECTION_FLAGS_FIELD_SIZE + \
                 ASF_PACKET_ERROR_CORRECTION_DATA_SIZE + \
                 1 + /*Length Type Flags*/ \
                 1 + /*Property Flags*/ \
                 ASF_PPI_PACKET_LENGTH_FIELD_SIZE + \
                 ASF_PPI_SEQUENCE_FIELD_SIZE + \
                 ASF_PPI_PADDING_LENGTH_FIELD_SIZE + \
                 4 + /*Send Time Field*/ \
                 2   /*Duration Field*/ \
                 )

 
 
 // Replicated Data shall be at least 8 bytes long.
 #define ASF_PAYLOAD_REPLICATED_DATA_LENGTH 0x08
 
 #define PAYLOAD_HEADER_SIZE_SINGLE_PAYLOAD (\

                 1 + /*Stream Number*/ \
                 ASF_PAYLOAD_MEDIA_OBJECT_NUMBER_FIELD_SIZE + \
                 ASF_PAYLOAD_OFFSET_INTO_MEDIA_OBJECT_FIELD_SIZE + \
                 ASF_PAYLOAD_REPLICATED_DATA_LENGTH_FIELD_SIZE + \
                 ASF_PAYLOAD_REPLICATED_DATA_LENGTH \
                 )

 #define PAYLOAD_HEADER_SIZE_MULTIPLE_PAYLOADS (\

                 1 + /*Stream Number*/ \
                 ASF_PAYLOAD_MEDIA_OBJECT_NUMBER_FIELD_SIZE + \
                 ASF_PAYLOAD_OFFSET_INTO_MEDIA_OBJECT_FIELD_SIZE + \
                 ASF_PAYLOAD_REPLICATED_DATA_LENGTH_FIELD_SIZE + \
                 ASF_PAYLOAD_REPLICATED_DATA_LENGTH + \
                 ASF_PAYLOAD_LENGTH_FIELD_SIZE \
                 )

 
 #define SINGLE_PAYLOAD_DATA_LENGTH (\

                 PACKET_SIZE - \
                 PACKET_HEADER_MIN_SIZE - \
                 PAYLOAD_HEADER_SIZE_SINGLE_PAYLOAD \
                 )

 
 #define MULTI_PAYLOAD_CONSTANT (\

                 PACKET_SIZE - \
                 PACKET_HEADER_MIN_SIZE - \
                 1 - /*Payload Flags*/ \
                 2*PAYLOAD_HEADER_SIZE_MULTIPLE_PAYLOADS \
                 )

 typedef struct {
     uint32_t seqno;
     int is_streamed;
     ASFStream streams[128];              ///< it's max number and it's not that big
     /* non streamed additonnal info */
     uint64_t nb_packets;                 ///< how many packets are there in the file, invalid if broadcasting
     int64_t duration;                    ///< in 100ns units
     /* packet filling */
     unsigned char multi_payloads_present;
     int packet_size_left;

     int64_t packet_timestamp_start;
     int64_t packet_timestamp_end;

     unsigned int packet_nb_payloads;
     uint8_t packet_buf[PACKET_SIZE];

     AVIOContext pb;

     /* only for reading */
     uint64_t data_offset;                ///< beginning of the first data packet
 
     ASFIndex* index_ptr;
     uint32_t nb_index_memory_alloc;
     uint16_t maximum_packet;

     uint32_t next_packet_number;
     uint16_t next_packet_count;
     int      next_start_sec;
     int      end_sec;

 } ASFContext;
 

 static const AVCodecTag codec_asf_bmp_tags[] = {

     { AV_CODEC_ID_MPEG4, MKTAG('M', '4', 'S', '2') },

     { AV_CODEC_ID_MPEG4, MKTAG('M', 'P', '4', 'S') },

     { AV_CODEC_ID_MSMPEG4V3, MKTAG('M', 'P', '4', '3') },
     { AV_CODEC_ID_NONE, 0 },

 };
 

 #define PREROLL_TIME 3100

 void ff_put_guid(AVIOContext *s, const ff_asf_guid *g)

 {

     assert(sizeof(*g) == 16);

     avio_write(s, *g, sizeof(*g));

 }
 

 static void put_str16(AVIOContext *s, const char *tag)

 {
     int len;
     uint8_t *pb;

     AVIOContext *dyn_buf;

     if (avio_open_dyn_buf(&dyn_buf) < 0)

         return;
 

     avio_put_str16le(dyn_buf, tag);

     len = avio_close_dyn_buf(dyn_buf, &pb);

     avio_wl16(s, len);
     avio_write(s, pb, len);

     av_freep(&pb);

 }
 

 static int64_t put_header(AVIOContext *pb, const ff_asf_guid *g)

 {
     int64_t pos;
 

     pos = avio_tell(pb);

     ff_put_guid(pb, g);

     avio_wl64(pb, 24);

     return pos;
 }
 
 /* update header size */

 static void end_header(AVIOContext *pb, int64_t pos)

 {
     int64_t pos1;
 

     pos1 = avio_tell(pb);

     avio_seek(pb, pos + 16, SEEK_SET);

     avio_wl64(pb, pos1 - pos);

     avio_seek(pb, pos1, SEEK_SET);

 }
 
 /* write an asf chunk (only used in streaming case) */
 static void put_chunk(AVFormatContext *s, int type, int payload_length, int flags)
 {
     ASFContext *asf = s->priv_data;

     AVIOContext *pb = s->pb;

     int length;
 
     length = payload_length + 8;

     avio_wl16(pb, type);
     avio_wl16(pb, length);    //size
     avio_wl32(pb, asf->seqno);//sequence number
     avio_wl16(pb, flags); /* unknown bytes */
     avio_wl16(pb, length);    //size_confirm

     asf->seqno++;
 }
 
 /* convert from unix to windows time */
 static int64_t unix_to_file_time(int ti)
 {
     int64_t t;
 

     t = ti * INT64_C(10000000);
     t += INT64_C(116444736000000000);

     return t;
 }
 
 /* write the header (used two times if non streamed) */
 static int asf_write_header1(AVFormatContext *s, int64_t file_size, int64_t data_chunk_size)
 {
     ASFContext *asf = s->priv_data;

     AVIOContext *pb = s->pb;

     AVDictionaryEntry *tags[5];

     int header_size, n, extra_size, extra_size2, wav_extra_size, file_time;
     int has_title;

     int metadata_count;

     AVCodecContext *enc;
     int64_t header_offset, cur_pos, hpos;
     int bit_rate;

     int64_t duration;

     ff_metadata_conv(&s->metadata, ff_asf_metadata_conv, NULL);

     tags[0] = av_dict_get(s->metadata, "title"    , NULL, 0);
     tags[1] = av_dict_get(s->metadata, "author"   , NULL, 0);
     tags[2] = av_dict_get(s->metadata, "copyright", NULL, 0);
     tags[3] = av_dict_get(s->metadata, "comment"  , NULL, 0);
     tags[4] = av_dict_get(s->metadata, "rating"   , NULL, 0);

     duration = asf->duration + PREROLL_TIME * 10000;

     has_title = tags[0] || tags[1] || tags[2] || tags[3] || tags[4];

     metadata_count = av_dict_count(s->metadata);

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

         enc = s->streams[n]->codec;

         avpriv_set_pts_info(s->streams[n], 32, 1, 1000); /* 32 bit pts in ms */

         bit_rate += enc->bit_rate;
     }
 
     if (asf->is_streamed) {
         put_chunk(s, 0x4824, 0, 0xc00); /* start of stream (length will be patched later) */
     }
 

     ff_put_guid(pb, &ff_asf_header);

     avio_wl64(pb, -1); /* header length, will be patched after */
     avio_wl32(pb, 3 + has_title + !!metadata_count + s->nb_streams); /* number of chunks in header */
     avio_w8(pb, 1); /* ??? */
     avio_w8(pb, 2); /* ??? */

 
     /* file header */

     header_offset = avio_tell(pb);

     hpos = put_header(pb, &ff_asf_file_header);

     ff_put_guid(pb, &ff_asf_my_guid);

     avio_wl64(pb, file_size);

     file_time = 0;

     avio_wl64(pb, unix_to_file_time(file_time));
     avio_wl64(pb, asf->nb_packets); /* number of packets */
     avio_wl64(pb, duration); /* end time stamp (in 100ns units) */
     avio_wl64(pb, asf->duration); /* duration (in 100ns units) */
     avio_wl64(pb, PREROLL_TIME); /* start time stamp */

     avio_wl32(pb, (asf->is_streamed || !pb->seekable ) ? 3 : 2); /* ??? */

     avio_wl32(pb, s->packet_size); /* packet size */
     avio_wl32(pb, s->packet_size); /* packet size */
     avio_wl32(pb, bit_rate); /* Nominal data rate in bps */

     end_header(pb, hpos);
 
     /* unknown headers */

     hpos = put_header(pb, &ff_asf_head1_guid);

     ff_put_guid(pb, &ff_asf_head2_guid);

     avio_wl32(pb, 6);
     avio_wl16(pb, 0);

     end_header(pb, hpos);
 
     /* title and other infos */
     if (has_title) {

         int len;
         uint8_t *buf;

         AVIOContext *dyn_buf;

         if (avio_open_dyn_buf(&dyn_buf) < 0)

             return AVERROR(ENOMEM);
 

         hpos = put_header(pb, &ff_asf_comment_header);

 
         for (n = 0; n < FF_ARRAY_ELEMS(tags); n++) {

             len = tags[n] ? avio_put_str16le(dyn_buf, tags[n]->value) : 0;

             avio_wl16(pb, len);

         }

         len = avio_close_dyn_buf(dyn_buf, &buf);

         avio_write(pb, buf, len);

         av_freep(&buf);

         end_header(pb, hpos);
     }

     if (metadata_count) {

         AVDictionaryEntry *tag = NULL;

         hpos = put_header(pb, &ff_asf_extended_content_header);

         avio_wl16(pb, metadata_count);

         while ((tag = av_dict_get(s->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {

             put_str16(pb, tag->key);

             avio_wl16(pb, 0);

             put_str16(pb, tag->value);

         }
         end_header(pb, hpos);
     }

 
     /* stream headers */
     for(n=0;n<s->nb_streams;n++) {
         int64_t es_pos;
         //        ASFStream *stream = &asf->streams[n];
 

         enc = s->streams[n]->codec;

         asf->streams[n].num = n + 1;

         asf->streams[n].seq = 1;

         switch(enc->codec_type) {

         case AVMEDIA_TYPE_AUDIO:

             wav_extra_size = 0;
             extra_size = 18 + wav_extra_size;

             extra_size2 = 8;

             break;
         default:

         case AVMEDIA_TYPE_VIDEO:

             wav_extra_size = enc->extradata_size;
             extra_size = 0x33 + wav_extra_size;

             extra_size2 = 0;
             break;
         }
 

         hpos = put_header(pb, &ff_asf_stream_header);

         if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {

             ff_put_guid(pb, &ff_asf_audio_stream);
             ff_put_guid(pb, &ff_asf_audio_conceal_spread);

         } else {

             ff_put_guid(pb, &ff_asf_video_stream);
             ff_put_guid(pb, &ff_asf_video_conceal_none);

         }

         avio_wl64(pb, 0); /* ??? */

         es_pos = avio_tell(pb);

         avio_wl32(pb, extra_size); /* wav header len */
         avio_wl32(pb, extra_size2); /* additional data len */
         avio_wl16(pb, n + 1); /* stream number */
         avio_wl32(pb, 0); /* ??? */

         if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {

             /* WAVEFORMATEX header */

             int wavsize = ff_put_wav_header(pb, enc);

 
             if (wavsize < 0)
                 return -1;
             if (wavsize != extra_size) {

                 cur_pos = avio_tell(pb);

                 avio_seek(pb, es_pos, SEEK_SET);

                 avio_wl32(pb, wavsize); /* wav header len */

                 avio_seek(pb, cur_pos, SEEK_SET);

             }

             /* ERROR Correction */

             avio_w8(pb, 0x01);

             if(enc->codec_id == AV_CODEC_ID_ADPCM_G726 || !enc->block_align){

                 avio_wl16(pb, 0x0190);
                 avio_wl16(pb, 0x0190);

             }else{

                 avio_wl16(pb, enc->block_align);
                 avio_wl16(pb, enc->block_align);

             }

             avio_wl16(pb, 0x01);
             avio_w8(pb, 0x00);

         } else {

             avio_wl32(pb, enc->width);
             avio_wl32(pb, enc->height);
             avio_w8(pb, 2); /* ??? */
             avio_wl16(pb, 40 + enc->extradata_size); /* size */

 
             /* BITMAPINFOHEADER header */

             ff_put_bmp_header(pb, enc, ff_codec_bmp_tags, 1);

         }
         end_header(pb, hpos);
     }
 
     /* media comments */
 

     hpos = put_header(pb, &ff_asf_codec_comment_header);

     ff_put_guid(pb, &ff_asf_codec_comment1_header);

     avio_wl32(pb, s->nb_streams);

     for(n=0;n<s->nb_streams;n++) {
         AVCodec *p;

         const char *desc;

         int len;
         uint8_t *buf;

         AVIOContext *dyn_buf;

         enc = s->streams[n]->codec;

         p = avcodec_find_encoder(enc->codec_id);
 

         if(enc->codec_type == AVMEDIA_TYPE_AUDIO)

             avio_wl16(pb, 2);

         else if(enc->codec_type == AVMEDIA_TYPE_VIDEO)

             avio_wl16(pb, 1);

         else

             avio_wl16(pb, -1);

         if(enc->codec_id == AV_CODEC_ID_WMAV2)

             desc = "Windows Media Audio V8";

         else

             desc = p ? p->name : enc->codec_name;

         if ( avio_open_dyn_buf(&dyn_buf) < 0)

             return AVERROR(ENOMEM);
 

         avio_put_str16le(dyn_buf, desc);

         len = avio_close_dyn_buf(dyn_buf, &buf);

         avio_wl16(pb, len / 2); // "number of characters" = length in bytes / 2

         avio_write(pb, buf, len);

         av_freep(&buf);
 

         avio_wl16(pb, 0); /* no parameters */

         /* id */

         if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {

             avio_wl16(pb, 2);
             avio_wl16(pb, enc->codec_tag);

         } else {

             avio_wl16(pb, 4);
             avio_wl32(pb, enc->codec_tag);

         }

         if(!enc->codec_tag)
             return -1;

     }
     end_header(pb, hpos);
 
     /* patch the header size fields */
 

     cur_pos = avio_tell(pb);

     header_size = cur_pos - header_offset;
     if (asf->is_streamed) {
         header_size += 8 + 30 + 50;
 

         avio_seek(pb, header_offset - 10 - 30, SEEK_SET);

         avio_wl16(pb, header_size);

         avio_seek(pb, header_offset - 2 - 30, SEEK_SET);

         avio_wl16(pb, header_size);

 
         header_size -= 8 + 30 + 50;
     }
     header_size += 24 + 6;

     avio_seek(pb, header_offset - 14, SEEK_SET);

     avio_wl64(pb, header_size);

     avio_seek(pb, cur_pos, SEEK_SET);

 
     /* movie chunk, followed by packets of packet_size */
     asf->data_offset = cur_pos;

     ff_put_guid(pb, &ff_asf_data_header);

     avio_wl64(pb, data_chunk_size);

     ff_put_guid(pb, &ff_asf_my_guid);

     avio_wl64(pb, asf->nb_packets); /* nb packets */
     avio_w8(pb, 1); /* ??? */
     avio_w8(pb, 1); /* ??? */

     return 0;
 }
 
 static int asf_write_header(AVFormatContext *s)
 {
     ASFContext *asf = s->priv_data;
 

     s->packet_size  = PACKET_SIZE;

     asf->nb_packets = 0;

     asf->index_ptr = av_malloc( sizeof(ASFIndex) * ASF_INDEX_BLOCK );

     asf->nb_index_memory_alloc = ASF_INDEX_BLOCK;
     asf->maximum_packet = 0;

     /* the data-chunk-size has to be 50, which is data_size - asf->data_offset
      *  at the moment this function is done. It is needed to use asf as
      *  streamable format. */
     if (asf_write_header1(s, 0, 50) < 0) {

         //av_free(asf);
         return -1;
     }
 

     avio_flush(s->pb);

     asf->packet_nb_payloads = 0;

     asf->packet_timestamp_start = -1;
     asf->packet_timestamp_end = -1;

     ffio_init_context(&asf->pb, asf->packet_buf, s->packet_size, 1,

                   NULL, NULL, NULL, NULL);
 

     if (s->avoid_negative_ts < 0)
         s->avoid_negative_ts = 1;
 

     return 0;
 }
 
 static int asf_write_stream_header(AVFormatContext *s)
 {
     ASFContext *asf = s->priv_data;
 
     asf->is_streamed = 1;
 
     return asf_write_header(s);
 }
 

 static int put_payload_parsing_info(
                                 AVFormatContext *s,

                                 unsigned int    sendtime,

                                 unsigned int    duration,

                                 int             nb_payloads,

                                 int             padsize
             )

 {
     ASFContext *asf = s->priv_data;

     AVIOContext *pb = s->pb;

     int ppi_size, i;

     int64_t start= avio_tell(pb);

 
     int iLengthTypeFlags = ASF_PPI_LENGTH_TYPE_FLAGS;

     padsize -= PACKET_HEADER_MIN_SIZE;
     if(asf->multi_payloads_present)
         padsize--;
     assert(padsize>=0);
 

     avio_w8(pb, ASF_PACKET_ERROR_CORRECTION_FLAGS);

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

         avio_w8(pb, 0x0);

     }
 

     if (asf->multi_payloads_present)
         iLengthTypeFlags |= ASF_PPI_FLAG_MULTIPLE_PAYLOADS_PRESENT;

 
     if (padsize > 0) {
         if (padsize < 256)

             iLengthTypeFlags |= ASF_PPI_FLAG_PADDING_LENGTH_FIELD_IS_BYTE;

         else

             iLengthTypeFlags |= ASF_PPI_FLAG_PADDING_LENGTH_FIELD_IS_WORD;

     }

     avio_w8(pb, iLengthTypeFlags);

     avio_w8(pb, ASF_PPI_PROPERTY_FLAGS);

 
     if (iLengthTypeFlags & ASF_PPI_FLAG_PADDING_LENGTH_FIELD_IS_WORD)

         avio_wl16(pb, padsize - 2);

     if (iLengthTypeFlags & ASF_PPI_FLAG_PADDING_LENGTH_FIELD_IS_BYTE)

         avio_w8(pb, padsize - 1);

     avio_wl32(pb, sendtime);
     avio_wl16(pb, duration);

     if (asf->multi_payloads_present)

         avio_w8(pb, nb_payloads | ASF_PAYLOAD_FLAGS);

     ppi_size = avio_tell(pb) - start;

     return ppi_size;

 }
 
 static void flush_packet(AVFormatContext *s)
 {
     ASFContext *asf = s->priv_data;

     int packet_hdr_size, packet_filled_size;

     assert(asf->packet_timestamp_end >= asf->packet_timestamp_start);
 

     if (asf->is_streamed) {

         put_chunk(s, 0x4424, s->packet_size, 0);

     }
 
     packet_hdr_size = put_payload_parsing_info(
                             s,
                             asf->packet_timestamp_start,
                             asf->packet_timestamp_end - asf->packet_timestamp_start,
                             asf->packet_nb_payloads,
                             asf->packet_size_left
                         );

     packet_filled_size = PACKET_SIZE - asf->packet_size_left;
     assert(packet_hdr_size <= asf->packet_size_left);

     memset(asf->packet_buf + packet_filled_size, 0, asf->packet_size_left);

     avio_write(s->pb, asf->packet_buf, s->packet_size - packet_hdr_size);

     avio_flush(s->pb);

     asf->nb_packets++;

     asf->packet_nb_payloads = 0;

     asf->packet_timestamp_start = -1;
     asf->packet_timestamp_end = -1;

     ffio_init_context(&asf->pb, asf->packet_buf, s->packet_size, 1,

                   NULL, NULL, NULL, NULL);
 }
 

 static void put_payload_header(
                                 AVFormatContext *s,
                                 ASFStream       *stream,

                                 int64_t         presentation_time,

                                 int             m_obj_size,
                                 int             m_obj_offset,

                                 int             payload_len,
                                 int             flags

             )

 {
     ASFContext *asf = s->priv_data;

     AVIOContext *pb = &asf->pb;

     int val;

     val = stream->num;

     if (flags & AV_PKT_FLAG_KEY)

         val |= ASF_PL_FLAG_KEY_FRAME;

     avio_w8(pb, val);

     avio_w8(pb, stream->seq);  //Media object number
     avio_wl32(pb, m_obj_offset); //Offset Into Media Object

     // Replicated Data shall be at least 8 bytes long.

     // The first 4 bytes of data shall contain the

     // Size of the Media Object that the payload belongs to.

     // The next 4 bytes of data shall contain the

     // Presentation Time for the media object that the payload belongs to.

     avio_w8(pb, ASF_PAYLOAD_REPLICATED_DATA_LENGTH);

     avio_wl32(pb, m_obj_size);       //Replicated Data - Media Object Size

     avio_wl32(pb, (uint32_t) presentation_time);//Replicated Data - Presentation Time

     if (asf->multi_payloads_present){

         avio_wl16(pb, payload_len);   //payload length

     }

 }
 

 static void put_frame(
                     AVFormatContext *s,
                     ASFStream       *stream,

                     AVStream        *avst,

                     int64_t         timestamp,

                     const uint8_t   *buf,

                     int             m_obj_size,

                     int             flags

                 )

 {
     ASFContext *asf = s->priv_data;

     int m_obj_offset, payload_len, frag_len1;
 
     m_obj_offset = 0;
     while (m_obj_offset < m_obj_size) {
         payload_len = m_obj_size - m_obj_offset;
         if (asf->packet_timestamp_start == -1) {
             asf->multi_payloads_present = (payload_len < MULTI_PAYLOAD_CONSTANT);

             asf->packet_size_left = PACKET_SIZE;

             if (asf->multi_payloads_present){
                 frag_len1 = MULTI_PAYLOAD_CONSTANT - 1;
             }
             else {
                 frag_len1 = SINGLE_PAYLOAD_DATA_LENGTH;
             }

             asf->packet_timestamp_start = timestamp;

         }
         else {
             // multi payloads

             frag_len1 = asf->packet_size_left - PAYLOAD_HEADER_SIZE_MULTIPLE_PAYLOADS - PACKET_HEADER_MIN_SIZE - 1;

             if(frag_len1 < payload_len && avst->codec->codec_type == AVMEDIA_TYPE_AUDIO){

                 flush_packet(s);
                 continue;
             }

         }

         if (frag_len1 > 0) {

             if (payload_len > frag_len1)
                 payload_len = frag_len1;
             else if (payload_len == (frag_len1 - 1))
                 payload_len = frag_len1 - 2;  //additional byte need to put padding length

             put_payload_header(s, stream, timestamp+PREROLL_TIME, m_obj_size, m_obj_offset, payload_len, flags);

             avio_write(&asf->pb, buf, payload_len);

 
             if (asf->multi_payloads_present)
                 asf->packet_size_left -= (payload_len + PAYLOAD_HEADER_SIZE_MULTIPLE_PAYLOADS);
             else
                 asf->packet_size_left -= (payload_len + PAYLOAD_HEADER_SIZE_SINGLE_PAYLOAD);

             asf->packet_timestamp_end = timestamp;

             asf->packet_nb_payloads++;

         } else {

             payload_len = 0;

         }

         m_obj_offset += payload_len;
         buf += payload_len;
 
         if (!asf->multi_payloads_present)
             flush_packet(s);

         else if (asf->packet_size_left <= (PAYLOAD_HEADER_SIZE_MULTIPLE_PAYLOADS + PACKET_HEADER_MIN_SIZE + 1))

             flush_packet(s);
     }
     stream->seq++;
 }
 

 static void update_index(AVFormatContext *s, int start_sec,
                          uint32_t packet_number, uint16_t packet_count)
 {
     ASFContext *asf = s->priv_data;
 
     if (start_sec > asf->next_start_sec) {
         int i;
 
         if (!asf->next_start_sec) {
             asf->next_packet_number = packet_number;
             asf->next_packet_count  = packet_count;
         }
 
         if (start_sec > asf->nb_index_memory_alloc) {
             asf->nb_index_memory_alloc = (start_sec + ASF_INDEX_BLOCK) & ~(ASF_INDEX_BLOCK - 1);
             asf->index_ptr = av_realloc( asf->index_ptr, sizeof(ASFIndex) * asf->nb_index_memory_alloc );
         }
         for (i = asf->next_start_sec; i < start_sec; i++) {
             asf->index_ptr[i].packet_number = asf->next_packet_number;
             asf->index_ptr[i].packet_count  = asf->next_packet_count;
         }
     }
     asf->maximum_packet     = FFMAX(asf->maximum_packet, packet_count);
     asf->next_packet_number = packet_number;
     asf->next_packet_count  = packet_count;
     asf->next_start_sec     = start_sec;
 }
 

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

 {
     ASFContext *asf = s->priv_data;
     ASFStream *stream;
     AVCodecContext *codec;

     uint32_t packet_number;
     int64_t pts;

     int start_sec;

     int flags= pkt->flags;

     codec = s->streams[pkt->stream_index]->codec;

     stream = &asf->streams[pkt->stream_index];

     if(codec->codec_type == AVMEDIA_TYPE_AUDIO)

         flags &= ~AV_PKT_FLAG_KEY;

     pts = (pkt->pts != AV_NOPTS_VALUE) ? pkt->pts : pkt->dts;

     assert(pts != AV_NOPTS_VALUE);

     pts *= 10000;
     asf->duration= FFMAX(asf->duration, pts + pkt->duration * 10000);

     packet_number = asf->nb_packets;

     put_frame(s, stream, s->streams[pkt->stream_index], pkt->dts, pkt->data, pkt->size, flags);

     start_sec = (int)((PREROLL_TIME * 10000 + pts + ASF_INDEXED_INTERVAL - 1)
               / ASF_INDEXED_INTERVAL);
 

     /* check index */

     if ((!asf->is_streamed) && (flags & AV_PKT_FLAG_KEY)) {

         uint16_t packet_count = asf->nb_packets - packet_number;

         update_index(s, start_sec, packet_number, packet_count);

     }

     asf->end_sec = start_sec;
 

     return 0;
 }
 
 //
 static int asf_write_index(AVFormatContext *s, ASFIndex *index, uint16_t max, uint32_t count)
 {

     AVIOContext *pb = s->pb;

     int i;
 

     ff_put_guid(pb, &ff_asf_simple_index_header);

     avio_wl64(pb, 24 + 16 + 8 + 4 + 4 + (4 + 2)*count);

     ff_put_guid(pb, &ff_asf_my_guid);

     avio_wl64(pb, ASF_INDEXED_INTERVAL);
     avio_wl32(pb, max);
     avio_wl32(pb, count);

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

         avio_wl32(pb, index[i].packet_number);
         avio_wl16(pb, index[i].packet_count);

     }
 

     return 0;
 }
 
 static int asf_write_trailer(AVFormatContext *s)
 {
     ASFContext *asf = s->priv_data;

     int64_t file_size,data_size;

 
     /* flush the current packet */
     if (asf->pb.buf_ptr > asf->pb.buffer)
         flush_packet(s);
 

     /* write index */

     data_size = avio_tell(s->pb);

     if (!asf->is_streamed && asf->next_start_sec) {
         update_index(s, asf->end_sec + 1, 0, 0);
         asf_write_index(s, asf->index_ptr, asf->maximum_packet, asf->next_start_sec);

     }

     avio_flush(s->pb);

     if (asf->is_streamed || !s->pb->seekable) {

         put_chunk(s, 0x4524, 0, 0); /* end of stream */
     } else {
         /* rewrite an updated header */

         file_size = avio_tell(s->pb);

         avio_seek(s->pb, 0, SEEK_SET);

         asf_write_header1(s, file_size, data_size - asf->data_offset);

     }
 

     av_free(asf->index_ptr);

     return 0;
 }
 

 #if CONFIG_ASF_MUXER

 AVOutputFormat ff_asf_muxer = {

     .name           = "asf",

     .long_name      = NULL_IF_CONFIG_SMALL("ASF (Advanced / Active Streaming Format)"),

     .mime_type      = "video/x-ms-asf",
     .extensions     = "asf,wmv,wma",
     .priv_data_size = sizeof(ASFContext),

     .audio_codec    = AV_CODEC_ID_WMAV2,

     .video_codec    = AV_CODEC_ID_MSMPEG4V3,

     .write_header   = asf_write_header,
     .write_packet   = asf_write_packet,
     .write_trailer  = asf_write_trailer,

     .flags          = AVFMT_GLOBALHEADER,
     .codec_tag      = (const AVCodecTag* const []){
         codec_asf_bmp_tags, ff_codec_bmp_tags, ff_codec_wav_tags, 0
     },

 };

 #endif

 #if CONFIG_ASF_STREAM_MUXER

 AVOutputFormat ff_asf_stream_muxer = {

     .name           = "asf_stream",

     .long_name      = NULL_IF_CONFIG_SMALL("ASF (Advanced / Active Streaming Format)"),

     .mime_type      = "video/x-ms-asf",
     .extensions     = "asf,wmv,wma",
     .priv_data_size = sizeof(ASFContext),

     .audio_codec    = AV_CODEC_ID_WMAV2,

     .video_codec    = AV_CODEC_ID_MSMPEG4V3,

     .write_header   = asf_write_stream_header,
     .write_packet   = asf_write_packet,
     .write_trailer  = asf_write_trailer,

     .flags          = AVFMT_GLOBALHEADER,
     .codec_tag      = (const AVCodecTag* const []){
         codec_asf_bmp_tags, ff_codec_bmp_tags, ff_codec_wav_tags, 0
     },

 };

 #endif //CONFIG_ASF_STREAM_MUXER