PeerStreamer

/*

 * 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 "metadata.h"

#include "riff.h"

#include "asf.h"

#include "avio_internal.h"

#undef NDEBUG

#include <assert.h>

#define ASF_INDEXED_INTERVAL    10000000

#define ASF_INDEX_BLOCK         600

#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;

    int packet_timestamp_start;

    int 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

    int64_t last_indexed_pts;

    ASFIndex* index_ptr;

    uint32_t nb_index_count;

    uint32_t nb_index_memory_alloc;

    uint16_t maximum_packet;

} ASFContext;

static const AVCodecTag codec_asf_bmp_tags[] = {

    { CODEC_ID_MPEG4, MKTAG('M', 'P', '4', 'S') },

    { CODEC_ID_MPEG4, MKTAG('M', '4', 'S', '2') },

    { CODEC_ID_MSMPEG4V3, MKTAG('M', 'P', '4', '3') },

    { CODEC_ID_NONE, 0 },

};

#define PREROLL_TIME 3100

static void 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 (url_open_dyn_buf(&dyn_buf) < 0)

        return;

    avio_put_str16le(dyn_buf, tag);

    len = url_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);

    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;

    AVMetadataTag *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_metadata_get(s->metadata, "title"    , NULL, 0);

    tags[1] = av_metadata_get(s->metadata, "author"   , NULL, 0);

    tags[2] = av_metadata_get(s->metadata, "copyright", NULL, 0);

    tags[3] = av_metadata_get(s->metadata, "comment"  , NULL, 0);

    tags[4] = av_metadata_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 = s->metadata ? s->metadata->count : 0;

    bit_rate = 0;

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

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

        av_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) */

    }

    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);

    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 || url_is_streamed(pb)) ? 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);

    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 (url_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 = url_close_dyn_buf(dyn_buf, &buf);

        avio_write(pb, buf, len);

        av_freep(&buf);

        end_header(pb, hpos);

    }

    if (metadata_count) {

        AVMetadataTag *tag = NULL;

        hpos = put_header(pb, &ff_asf_extended_content_header);

        avio_wl16(pb, metadata_count);

        while ((tag = av_metadata_get(s->metadata, "", tag, AV_METADATA_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 = 0;

        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) {

            put_guid(pb, &ff_asf_audio_stream);

            put_guid(pb, &ff_asf_audio_conceal_spread);

        } else {

            put_guid(pb, &ff_asf_video_stream);

            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 ((enc->codec_id != CODEC_ID_MP3) && (enc->codec_id != CODEC_ID_MP2) && (enc->codec_id != CODEC_ID_ADPCM_IMA_WAV) && (enc->extradata_size==0)) {

                wavsize += 2;

                avio_wl16(pb, 0);

            }

            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 == 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);

    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 == CODEC_ID_WMAV2)

            desc = "Windows Media Audio V8";

        else

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

        if ( url_open_dyn_buf(&dyn_buf) < 0)

            return AVERROR(ENOMEM);

        avio_put_str16le(dyn_buf, desc);

        len = url_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;

    put_guid(pb, &ff_asf_data_header);

    avio_wl64(pb, data_chunk_size);

    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->last_indexed_pts = 0;

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

    asf->nb_index_memory_alloc = ASF_INDEX_BLOCK;

    asf->nb_index_count = 0;

    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);

    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,

                                int             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, 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,

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

{

    ASFContext *asf = s->priv_data;

    ASFStream *stream;

    int64_t duration;

    AVCodecContext *codec;

    int64_t packet_st,pts;

    int start_sec,i;

    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);

    duration = pts * 10000;

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

    packet_st = asf->nb_packets;

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

    /* check index */

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

        start_sec = (int)(duration / INT64_C(10000000));

        if (start_sec != (int)(asf->last_indexed_pts / INT64_C(10000000))) {

            for(i=asf->nb_index_count;i<start_sec;i++) {

                if (i>=asf->nb_index_memory_alloc) {

                    asf->nb_index_memory_alloc += ASF_INDEX_BLOCK;

                    asf->index_ptr = (ASFIndex*)av_realloc( asf->index_ptr, sizeof(ASFIndex) * asf->nb_index_memory_alloc );

                }

                // store

                asf->index_ptr[i].packet_number = (uint32_t)packet_st;

                asf->index_ptr[i].packet_count  = (uint16_t)(asf->nb_packets-packet_st);

                asf->maximum_packet = FFMAX(asf->maximum_packet, (uint16_t)(asf->nb_packets-packet_st));

            }

            asf->nb_index_count = start_sec;

            asf->last_indexed_pts = duration;

        }

    }

    return 0;

}

//

static int asf_write_index(AVFormatContext *s, ASFIndex *index, uint16_t max, uint32_t count)

{

    AVIOContext *pb = s->pb;

    int i;

    put_guid(pb, &ff_asf_simple_index_header);

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

    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->nb_index_count != 0)) {

        asf_write_index(s, asf->index_ptr, asf->maximum_packet, asf->nb_index_count);

    }

    avio_flush(s->pb);

    if (asf->is_streamed || url_is_streamed(s->pb)) {

        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);

    }

    avio_flush(s->pb);

    av_free(asf->index_ptr);

    return 0;

}

#if CONFIG_ASF_MUXER

AVOutputFormat ff_asf_muxer = {

    "asf",

    NULL_IF_CONFIG_SMALL("ASF format"),

    "video/x-ms-asf",

    "asf,wmv,wma",

    sizeof(ASFContext),

#if CONFIG_LIBMP3LAME

    CODEC_ID_MP3,

#else

    CODEC_ID_MP2,

#endif

    CODEC_ID_MSMPEG4V3,

    asf_write_header,

    asf_write_packet,

    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 = {

    "asf_stream",

    NULL_IF_CONFIG_SMALL("ASF format"),

    "video/x-ms-asf",

    "asf,wmv,wma",

    sizeof(ASFContext),

#if CONFIG_LIBMP3LAME

    CODEC_ID_MP3,

#else

    CODEC_ID_MP2,

#endif

    CODEC_ID_MSMPEG4V3,

    asf_write_stream_header,

    asf_write_packet,

    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