PeerStreamer

/*

 * ASF compatible decoder.

 * Copyright (c) 2000, 2001 Fabrice Bellard.

 *

 * This library 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 of the License, or (at your option) any later version.

 *

 * This library 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 this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include "avformat.h"

#include "avi.h"

#include "mpegaudio.h"

#include "asf.h"

#undef NDEBUG

#include <assert.h>

#define FRAME_HEADER_SIZE 17

// Fix Me! FRAME_HEADER_SIZE may be different.

static const GUID index_guid = {

    0x33000890, 0xe5b1, 0x11cf, { 0x89, 0xf4, 0x00, 0xa0, 0xc9, 0x03, 0x49, 0xcb },

};

/**********************************/

/* decoding */

//#define DEBUG

#ifdef DEBUG

#define PRINT_IF_GUID(g,cmp) \

if (!memcmp(g, &cmp, sizeof(GUID))) \

    printf("(GUID: %s) ", #cmp)

static void print_guid(const GUID *g)

{

    int i;

    PRINT_IF_GUID(g, asf_header);

    else PRINT_IF_GUID(g, file_header);

    else PRINT_IF_GUID(g, stream_header);

    else PRINT_IF_GUID(g, audio_stream);

    else PRINT_IF_GUID(g, audio_conceal_none);

    else PRINT_IF_GUID(g, video_stream);

    else PRINT_IF_GUID(g, video_conceal_none);

    else PRINT_IF_GUID(g, command_stream);

    else PRINT_IF_GUID(g, comment_header);

    else PRINT_IF_GUID(g, codec_comment_header);

    else PRINT_IF_GUID(g, codec_comment1_header);

    else PRINT_IF_GUID(g, data_header);

    else PRINT_IF_GUID(g, index_guid);

    else PRINT_IF_GUID(g, head1_guid);

    else PRINT_IF_GUID(g, head2_guid);

    else PRINT_IF_GUID(g, my_guid);

    else

        printf("(GUID: unknown) ");

    printf("0x%08x, 0x%04x, 0x%04x, {", g->v1, g->v2, g->v3);

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

        printf(" 0x%02x,", g->v4[i]);

    printf("}\n");

}

#undef PRINT_IF_GUID(g,cmp)

#endif

static void get_guid(ByteIOContext *s, GUID *g)

{

    int i;

    g->v1 = get_le32(s);

    g->v2 = get_le16(s);

    g->v3 = get_le16(s);

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

        g->v4[i] = get_byte(s);

}

#if 0

static void get_str16(ByteIOContext *pb, char *buf, int buf_size)

{

    int len, c;

    char *q;

    len = get_le16(pb);

    q = buf;

    while (len > 0) {

        c = get_le16(pb);

        if ((q - buf) < buf_size - 1)

            *q++ = c;

        len--;

    }

    *q = '\0';

}

#endif

static void get_str16_nolen(ByteIOContext *pb, int len, char *buf, int buf_size)

{

    int c;

    char *q;

    q = buf;

    while (len > 0) {

        c = get_le16(pb);

        if ((q - buf) < buf_size - 1)

            *q++ = c;

        len-=2;

    }

    *q = '\0';

}

static int asf_probe(AVProbeData *pd)

{

    GUID g;

    const unsigned char *p;

    int i;

    /* check file header */

    if (pd->buf_size <= 32)

        return 0;

    p = pd->buf;

    g.v1 = p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);

    p += 4;

    g.v2 = p[0] | (p[1] << 8);

    p += 2;

    g.v3 = p[0] | (p[1] << 8);

    p += 2;

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

        g.v4[i] = *p++;

    if (!memcmp(&g, &asf_header, sizeof(GUID)))

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

static int asf_read_header(AVFormatContext *s, AVFormatParameters *ap)

{

    ASFContext *asf = s->priv_data;

    GUID g;

    ByteIOContext *pb = &s->pb;

    AVStream *st;

    ASFStream *asf_st;

    int size, i;

    int64_t gsize;

    get_guid(pb, &g);

    if (memcmp(&g, &asf_header, sizeof(GUID)))

        goto fail;

    get_le64(pb);

    get_le32(pb);

    get_byte(pb);

    get_byte(pb);

    memset(&asf->asfid2avid, -1, sizeof(asf->asfid2avid));

    for(;;) {

        get_guid(pb, &g);

        gsize = get_le64(pb);

#ifdef DEBUG

        printf("%08Lx: ", url_ftell(pb) - 24);

        print_guid(&g);

        printf("  size=0x%Lx\n", gsize);

#endif

        if (gsize < 24)

            goto fail;

        if (!memcmp(&g, &file_header, sizeof(GUID))) {

            get_guid(pb, &asf->hdr.guid);

            asf->hdr.file_size          = get_le64(pb);

            asf->hdr.create_time        = get_le64(pb);

            asf->hdr.packets_count      = get_le64(pb);

            asf->hdr.send_time          = get_le64(pb);

            asf->hdr.play_time          = get_le64(pb);

            asf->hdr.preroll            = get_le32(pb);

            asf->hdr.ignore             = get_le32(pb);

            asf->hdr.flags              = get_le32(pb);

            asf->hdr.min_pktsize        = get_le32(pb);

            asf->hdr.max_pktsize        = get_le32(pb);

            asf->hdr.max_bitrate        = get_le32(pb);

            asf->packet_size = asf->hdr.max_pktsize;

            asf->nb_packets = asf->hdr.packets_count;

        } else if (!memcmp(&g, &stream_header, sizeof(GUID))) {

            int type, total_size, type_specific_size, sizeX;

            unsigned int tag1;

            int64_t pos1, pos2;

            pos1 = url_ftell(pb);

            st = av_new_stream(s, 0);

            if (!st)

                goto fail;

            av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */

            asf_st = av_mallocz(sizeof(ASFStream));

            if (!asf_st)

                goto fail;

            st->priv_data = asf_st;

            st->start_time = asf->hdr.preroll;

            st->duration = asf->hdr.send_time /

                (10000000 / 1000) - st->start_time;

            get_guid(pb, &g);

            if (!memcmp(&g, &audio_stream, sizeof(GUID))) {

                type = CODEC_TYPE_AUDIO;

            } else if (!memcmp(&g, &video_stream, sizeof(GUID))) {

                type = CODEC_TYPE_VIDEO;

            } else if (!memcmp(&g, &command_stream, sizeof(GUID))) {

                type = CODEC_TYPE_UNKNOWN;

            } else {

                goto fail;

            }

            get_guid(pb, &g);

            total_size = get_le64(pb);

            type_specific_size = get_le32(pb);

            get_le32(pb);

            st->id = get_le16(pb) & 0x7f; /* stream id */

            // mapping of asf ID to AV stream ID;

            asf->asfid2avid[st->id] = s->nb_streams - 1;

            get_le32(pb);

            st->codec->codec_type = type;

            if (type == CODEC_TYPE_AUDIO) {

                get_wav_header(pb, st->codec, type_specific_size);

                st->need_parsing = 1;

                /* We have to init the frame size at some point .... */

                pos2 = url_ftell(pb);

                if (gsize > (pos2 + 8 - pos1 + 24)) {

                    asf_st->ds_span = get_byte(pb);

                    asf_st->ds_packet_size = get_le16(pb);

                    asf_st->ds_chunk_size = get_le16(pb);

                    asf_st->ds_data_size = get_le16(pb);

                    asf_st->ds_silence_data = get_byte(pb);

                }

                //printf("Descrambling: ps:%d cs:%d ds:%d s:%d  sd:%d\n",

                //       asf_st->ds_packet_size, asf_st->ds_chunk_size,

                //       asf_st->ds_data_size, asf_st->ds_span, asf_st->ds_silence_data);

                if (asf_st->ds_span > 1) {

                    if (!asf_st->ds_chunk_size

                        || (asf_st->ds_packet_size/asf_st->ds_chunk_size <= 1))

                        asf_st->ds_span = 0; // disable descrambling

                }

                switch (st->codec->codec_id) {

                case CODEC_ID_MP3:

                    st->codec->frame_size = MPA_FRAME_SIZE;

                    break;

                case CODEC_ID_PCM_S16LE:

                case CODEC_ID_PCM_S16BE:

                case CODEC_ID_PCM_U16LE:

                case CODEC_ID_PCM_U16BE:

                case CODEC_ID_PCM_S8:

                case CODEC_ID_PCM_U8:

                case CODEC_ID_PCM_ALAW:

                case CODEC_ID_PCM_MULAW:

                    st->codec->frame_size = 1;

                    break;

                default:

                    /* This is probably wrong, but it prevents a crash later */

                    st->codec->frame_size = 1;

                    break;

                }

            } else {

                get_le32(pb);

                get_le32(pb);

                get_byte(pb);

                size = get_le16(pb); /* size */

                sizeX= get_le32(pb); /* size */

                st->codec->width = get_le32(pb);

                st->codec->height = get_le32(pb);

                /* not available for asf */

                get_le16(pb); /* panes */

                st->codec->bits_per_sample = get_le16(pb); /* depth */

                tag1 = get_le32(pb);

                url_fskip(pb, 20);

//                av_log(NULL, AV_LOG_DEBUG, "size:%d tsize:%d sizeX:%d\n", size, total_size, sizeX);

                size= sizeX;

                if (size > 40) {

                    st->codec->extradata_size = size - 40;

                    st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

                    get_buffer(pb, st->codec->extradata, st->codec->extradata_size);

                }

        /* Extract palette from extradata if bpp <= 8 */

        /* This code assumes that extradata contains only palette */

        /* This is true for all paletted codecs implemented in ffmpeg */

        if (st->codec->extradata_size && (st->codec->bits_per_sample <= 8)) {

            st->codec->palctrl = av_mallocz(sizeof(AVPaletteControl));

#ifdef WORDS_BIGENDIAN

            for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE)/4; i++)

                st->codec->palctrl->palette[i] = bswap_32(((uint32_t*)st->codec->extradata)[i]);

#else

            memcpy(st->codec->palctrl->palette, st->codec->extradata,

                   FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));

#endif

            st->codec->palctrl->palette_changed = 1;

        }

                st->codec->codec_tag = tag1;

                st->codec->codec_id = codec_get_id(codec_bmp_tags, tag1);

                if(tag1 == MKTAG('D', 'V', 'R', ' '))

                    st->need_parsing = 1;

            }

            pos2 = url_ftell(pb);

            url_fskip(pb, gsize - (pos2 - pos1 + 24));

        } else if (!memcmp(&g, &data_header, sizeof(GUID))) {

            break;

        } else if (!memcmp(&g, &comment_header, sizeof(GUID))) {

            int len1, len2, len3, len4, len5;

            len1 = get_le16(pb);

            len2 = get_le16(pb);

            len3 = get_le16(pb);

            len4 = get_le16(pb);

            len5 = get_le16(pb);

            get_str16_nolen(pb, len1, s->title, sizeof(s->title));

            get_str16_nolen(pb, len2, s->author, sizeof(s->author));

            get_str16_nolen(pb, len3, s->copyright, sizeof(s->copyright));

            get_str16_nolen(pb, len4, s->comment, sizeof(s->comment));

            url_fskip(pb, len5);

       } else if (!memcmp(&g, &extended_content_header, sizeof(GUID))) {

                int desc_count, i;

                desc_count = get_le16(pb);

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

                {

                        int name_len,value_type,value_len,value_num = 0;

                        char *name, *value;

                        name_len = get_le16(pb);

                        name = (char *)av_mallocz(name_len);

                        get_str16_nolen(pb, name_len, name, name_len);

                        value_type = get_le16(pb);

                        value_len = get_le16(pb);

                        if ((value_type == 0) || (value_type == 1)) // unicode or byte

                        {

                                value = (char *)av_mallocz(value_len);

                                get_str16_nolen(pb, value_len, value, value_len);

                                if (strcmp(name,"WM/AlbumTitle")==0) { pstrcpy(s->album, sizeof(s->album), value); }

                                av_free(value);

                        }

                        if ((value_type >= 2) && (value_type <= 5)) // boolean or DWORD or QWORD or WORD

                        {

                                if (value_type==2) value_num = get_le32(pb);

                                if (value_type==3) value_num = get_le32(pb);

                                if (value_type==4) value_num = get_le64(pb);

                                if (value_type==5) value_num = get_le16(pb);

                                if (strcmp(name,"WM/Track")==0) s->track = value_num + 1;

                                if (strcmp(name,"WM/TrackNumber")==0) s->track = value_num;

                        }

                        av_free(name);

                }

#if 0

        } else if (!memcmp(&g, &head1_guid, sizeof(GUID))) {

            int v1, v2;

            get_guid(pb, &g);

            v1 = get_le32(pb);

            v2 = get_le16(pb);

        } else if (!memcmp(&g, &codec_comment_header, sizeof(GUID))) {

            int len, v1, n, num;

            char str[256], *q;

            char tag[16];

            get_guid(pb, &g);

            print_guid(&g);

            n = get_le32(pb);

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

                num = get_le16(pb); /* stream number */

                get_str16(pb, str, sizeof(str));

                get_str16(pb, str, sizeof(str));

                len = get_le16(pb);

                q = tag;

                while (len > 0) {

                    v1 = get_byte(pb);

                    if ((q - tag) < sizeof(tag) - 1)

                        *q++ = v1;

                    len--;

                }

                *q = '\0';

            }

#endif

        } else if (url_feof(pb)) {

            goto fail;

        } else {

            url_fseek(pb, gsize - 24, SEEK_CUR);

        }

    }

    get_guid(pb, &g);

    get_le64(pb);

    get_byte(pb);

    get_byte(pb);

    if (url_feof(pb))

        goto fail;

    asf->data_offset = url_ftell(pb);

    asf->packet_size_left = 0;

    return 0;

 fail:

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

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

        if (st) {

            av_free(st->priv_data);

            av_free(st->codec->extradata);

        }

        av_free(st);

    }

    return -1;

}

#define DO_2BITS(bits, var, defval) \

    switch (bits & 3) \

    { \

    case 3: var = get_le32(pb); rsize += 4; break; \

    case 2: var = get_le16(pb); rsize += 2; break; \

    case 1: var = get_byte(pb); rsize++; break; \

    default: var = defval; break; \

    }

static int asf_get_packet(AVFormatContext *s)

{

    ASFContext *asf = s->priv_data;

    ByteIOContext *pb = &s->pb;

    uint32_t packet_length, padsize;

    int rsize = 9;

    int c;

    assert((url_ftell(&s->pb) - s->data_offset) % asf->packet_size == 0);

    c = get_byte(pb);

    if (c != 0x82) {

        if (!url_feof(pb))

            av_log(s, AV_LOG_ERROR, "ff asf bad header %x  at:%"PRId64"\n", c, url_ftell(pb));

    }

    if ((c & 0x0f) == 2) { // always true for now

        if (get_le16(pb) != 0) {

            if (!url_feof(pb))

                av_log(s, AV_LOG_ERROR, "ff asf bad non zero\n");

            return AVERROR_IO;

        }

        rsize+=2;

/*    }else{

        if (!url_feof(pb))

            printf("ff asf bad header %x  at:%lld\n", c, url_ftell(pb));

        return AVERROR_IO;*/

    }

    asf->packet_flags = get_byte(pb);

    asf->packet_property = get_byte(pb);

    DO_2BITS(asf->packet_flags >> 5, packet_length, asf->packet_size);

    DO_2BITS(asf->packet_flags >> 1, padsize, 0); // sequence ignored

    DO_2BITS(asf->packet_flags >> 3, padsize, 0); // padding length

    asf->packet_timestamp = get_le32(pb);

    get_le16(pb); /* duration */

    // rsize has at least 11 bytes which have to be present

    if (asf->packet_flags & 0x01) {

        asf->packet_segsizetype = get_byte(pb); rsize++;

        asf->packet_segments = asf->packet_segsizetype & 0x3f;

    } else {

        asf->packet_segments = 1;

        asf->packet_segsizetype = 0x80;

    }

    asf->packet_size_left = packet_length - padsize - rsize;

    if (packet_length < asf->hdr.min_pktsize)

        padsize += asf->hdr.min_pktsize - packet_length;

    asf->packet_padsize = padsize;

#ifdef DEBUG

    printf("packet: size=%d padsize=%d  left=%d\n", asf->packet_size, asf->packet_padsize, asf->packet_size_left);

#endif

    return 0;

}

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

{

    ASFContext *asf = s->priv_data;

    ASFStream *asf_st = 0;

    ByteIOContext *pb = &s->pb;

    //static int pc = 0;

    for (;;) {

        int rsize = 0;

        if (asf->packet_size_left < FRAME_HEADER_SIZE

            || asf->packet_segments < 1) {

            //asf->packet_size_left <= asf->packet_padsize) {

            int ret = asf->packet_size_left + asf->packet_padsize;

            //printf("PacketLeftSize:%d  Pad:%d Pos:%Ld\n", asf->packet_size_left, asf->packet_padsize, url_ftell(pb));

            if((url_ftell(&s->pb) + ret - s->data_offset) % asf->packet_size)

                ret += asf->packet_size - ((url_ftell(&s->pb) + ret - s->data_offset) % asf->packet_size);

            /* fail safe */

            url_fskip(pb, ret);

            asf->packet_pos= url_ftell(&s->pb);

            ret = asf_get_packet(s);

            //printf("READ ASF PACKET  %d   r:%d   c:%d\n", ret, asf->packet_size_left, pc++);

            if (ret < 0 || url_feof(pb))

                return AVERROR_IO;

            asf->packet_time_start = 0;

            continue;

        }

        if (asf->packet_time_start == 0) {

            /* read frame header */

            int num = get_byte(pb);

            asf->packet_segments--;

            rsize++;

            asf->packet_key_frame = (num & 0x80) >> 7;

            asf->stream_index = asf->asfid2avid[num & 0x7f];

            // sequence should be ignored!

            DO_2BITS(asf->packet_property >> 4, asf->packet_seq, 0);

            DO_2BITS(asf->packet_property >> 2, asf->packet_frag_offset, 0);

            DO_2BITS(asf->packet_property, asf->packet_replic_size, 0);

//printf("key:%d stream:%d seq:%d offset:%d replic_size:%d\n", asf->packet_key_frame, asf->stream_index, asf->packet_seq, //asf->packet_frag_offset, asf->packet_replic_size);

            if (asf->packet_replic_size > 1) {

                assert(asf->packet_replic_size >= 8);

                // it should be always at least 8 bytes - FIXME validate

                asf->packet_obj_size = get_le32(pb);

                asf->packet_frag_timestamp = get_le32(pb); // timestamp

                if (asf->packet_replic_size > 8)

                    url_fskip(pb, asf->packet_replic_size - 8);

                rsize += asf->packet_replic_size; // FIXME - check validity

            } else if (asf->packet_replic_size==1){

                // multipacket - frag_offset is begining timestamp

                asf->packet_time_start = asf->packet_frag_offset;

                asf->packet_frag_offset = 0;

                asf->packet_frag_timestamp = asf->packet_timestamp;

                asf->packet_time_delta = get_byte(pb);

                rsize++;

            }else{

                assert(asf->packet_replic_size==0);

            }

            if (asf->packet_flags & 0x01) {

                DO_2BITS(asf->packet_segsizetype >> 6, asf->packet_frag_size, 0); // 0 is illegal

#undef DO_2BITS

                //printf("Fragsize %d\n", asf->packet_frag_size);

            } else {

                asf->packet_frag_size = asf->packet_size_left - rsize;

                //printf("Using rest  %d %d %d\n", asf->packet_frag_size, asf->packet_size_left, rsize);

            }

            if (asf->packet_replic_size == 1) {

                asf->packet_multi_size = asf->packet_frag_size;

                if (asf->packet_multi_size > asf->packet_size_left) {

                    asf->packet_segments = 0;

                    continue;

                }

            }

            asf->packet_size_left -= rsize;

            //printf("___objsize____  %d   %d    rs:%d\n", asf->packet_obj_size, asf->packet_frag_offset, rsize);

            if (asf->stream_index < 0

                || s->streams[asf->stream_index]->discard >= AVDISCARD_ALL

                || (!asf->packet_key_frame && s->streams[asf->stream_index]->discard >= AVDISCARD_NONKEY)

                ) {

                asf->packet_time_start = 0;

                /* unhandled packet (should not happen) */

                url_fskip(pb, asf->packet_frag_size);

                asf->packet_size_left -= asf->packet_frag_size;

                if(asf->stream_index < 0)

                    av_log(s, AV_LOG_ERROR, "ff asf skip %d  %d\n", asf->packet_frag_size, num & 0x7f);

                continue;

            }

            asf->asf_st = s->streams[asf->stream_index]->priv_data;

        }

        asf_st = asf->asf_st;

        if ((asf->packet_frag_offset != asf_st->frag_offset

             || (asf->packet_frag_offset

                 && asf->packet_seq != asf_st->seq)) // seq should be ignored

           ) {

            /* cannot continue current packet: free it */

            // FIXME better check if packet was already allocated

            av_log(s, AV_LOG_INFO, "ff asf parser skips: %d - %d     o:%d - %d    %d %d   fl:%d\n",

                   asf_st->pkt.size,

                   asf->packet_obj_size,

                   asf->packet_frag_offset, asf_st->frag_offset,

                   asf->packet_seq, asf_st->seq, asf->packet_frag_size);

            if (asf_st->pkt.size)

                av_free_packet(&asf_st->pkt);

            asf_st->frag_offset = 0;

            if (asf->packet_frag_offset != 0) {

                url_fskip(pb, asf->packet_frag_size);

                av_log(s, AV_LOG_INFO, "ff asf parser skipping %db\n", asf->packet_frag_size);

                asf->packet_size_left -= asf->packet_frag_size;

                continue;

            }

        }

        if (asf->packet_replic_size == 1) {

            // frag_offset is here used as the begining timestamp

            asf->packet_frag_timestamp = asf->packet_time_start;

            asf->packet_time_start += asf->packet_time_delta;

            asf->packet_obj_size = asf->packet_frag_size = get_byte(pb);

            asf->packet_size_left--;

            asf->packet_multi_size--;

            if (asf->packet_multi_size < asf->packet_obj_size)

            {

                asf->packet_time_start = 0;

                url_fskip(pb, asf->packet_multi_size);

                asf->packet_size_left -= asf->packet_multi_size;

                continue;

            }

            asf->packet_multi_size -= asf->packet_obj_size;

            //printf("COMPRESS size  %d  %d  %d   ms:%d\n", asf->packet_obj_size, asf->packet_frag_timestamp, asf->packet_size_left, asf->packet_multi_size);

        }

        if (asf_st->frag_offset == 0) {

            /* new packet */

            av_new_packet(&asf_st->pkt, asf->packet_obj_size);

            asf_st->seq = asf->packet_seq;

            asf_st->pkt.pts = asf->packet_frag_timestamp;

            asf_st->pkt.stream_index = asf->stream_index;

            asf_st->pkt.pos =

            asf_st->packet_pos= asf->packet_pos;

//printf("new packet: stream:%d key:%d packet_key:%d audio:%d size:%d\n",

//asf->stream_index, asf->packet_key_frame, asf_st->pkt.flags & PKT_FLAG_KEY,

//s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO, asf->packet_obj_size);

            if (s->streams[asf->stream_index]->codec->codec_type == CODEC_TYPE_AUDIO)

                asf->packet_key_frame = 1;

            if (asf->packet_key_frame)

                asf_st->pkt.flags |= PKT_FLAG_KEY;

        }

        /* read data */

        //printf("READ PACKET s:%d  os:%d  o:%d,%d  l:%d   DATA:%p\n",

        //       asf->packet_size, asf_st->pkt.size, asf->packet_frag_offset,

        //       asf_st->frag_offset, asf->packet_frag_size, asf_st->pkt.data);

        asf->packet_size_left -= asf->packet_frag_size;

        if (asf->packet_size_left < 0)

            continue;

        get_buffer(pb, asf_st->pkt.data + asf->packet_frag_offset,

                   asf->packet_frag_size);

        asf_st->frag_offset += asf->packet_frag_size;

        /* test if whole packet is read */

        if (asf_st->frag_offset == asf_st->pkt.size) {

            /* return packet */

            if (asf_st->ds_span > 1) {

                /* packet descrambling */

                char* newdata = av_malloc(asf_st->pkt.size);

                if (newdata) {

                    int offset = 0;

                    while (offset < asf_st->pkt.size) {

                        int off = offset / asf_st->ds_chunk_size;

                        int row = off / asf_st->ds_span;

                        int col = off % asf_st->ds_span;

                        int idx = row + col * asf_st->ds_packet_size / asf_st->ds_chunk_size;

                        //printf("off:%d  row:%d  col:%d  idx:%d\n", off, row, col, idx);

                        memcpy(newdata + offset,

                               asf_st->pkt.data + idx * asf_st->ds_chunk_size,

                               asf_st->ds_chunk_size);

                        offset += asf_st->ds_chunk_size;

                    }

                    av_free(asf_st->pkt.data);

                    asf_st->pkt.data = newdata;

                }

            }

            asf_st->frag_offset = 0;

            memcpy(pkt, &asf_st->pkt, sizeof(AVPacket));

            //printf("packet %d %d\n", asf_st->pkt.size, asf->packet_frag_size);

            asf_st->pkt.size = 0;

            asf_st->pkt.data = 0;

            break; // packet completed

        }

    }

    return 0;

}

static int asf_read_close(AVFormatContext *s)

{

    int i;

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

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

        av_free(st->priv_data);

        av_free(st->codec->extradata);

    av_free(st->codec->palctrl);

    }

    return 0;

}

// Added to support seeking after packets have been read

// If information is not reset, read_packet fails due to

// leftover information from previous reads

static void asf_reset_header(AVFormatContext *s)

{

    ASFContext *asf = s->priv_data;

    ASFStream *asf_st;

    int i;

    asf->packet_nb_frames = 0;

    asf->packet_timestamp_start = -1;

    asf->packet_timestamp_end = -1;

    asf->packet_size_left = 0;

    asf->packet_segments = 0;

    asf->packet_flags = 0;

    asf->packet_property = 0;

    asf->packet_timestamp = 0;

    asf->packet_segsizetype = 0;

    asf->packet_segments = 0;

    asf->packet_seq = 0;

    asf->packet_replic_size = 0;

    asf->packet_key_frame = 0;

    asf->packet_padsize = 0;

    asf->packet_frag_offset = 0;

    asf->packet_frag_size = 0;

    asf->packet_frag_timestamp = 0;

    asf->packet_multi_size = 0;

    asf->packet_obj_size = 0;

    asf->packet_time_delta = 0;

    asf->packet_time_start = 0;

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

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

        av_free_packet(&asf_st->pkt);

        asf_st->frag_offset=0;

        asf_st->seq=0;

    }

    asf->asf_st= NULL;

}

static int64_t asf_read_pts(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit)

{

    ASFContext *asf = s->priv_data;

    AVPacket pkt1, *pkt = &pkt1;

    ASFStream *asf_st;

    int64_t pts;

    int64_t pos= *ppos;

    int i;

    int64_t start_pos[s->nb_streams];

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

        start_pos[i]= pos;

    }

    pos= (pos+asf->packet_size-1-s->data_offset)/asf->packet_size*asf->packet_size+ s->data_offset;

    *ppos= pos;

    url_fseek(&s->pb, pos, SEEK_SET);

//printf("asf_read_pts\n");

    asf_reset_header(s);

    for(;;){

        if (av_read_frame(s, pkt) < 0){

            av_log(s, AV_LOG_INFO, "seek failed\n");

            return AV_NOPTS_VALUE;

        }

        pts= pkt->pts * 1000 / AV_TIME_BASE;

        av_free_packet(pkt);

        if(pkt->flags&PKT_FLAG_KEY){

            i= pkt->stream_index;

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

            assert((asf_st->packet_pos - s->data_offset) % asf->packet_size == 0);

            pos= asf_st->packet_pos;

            av_add_index_entry(s->streams[i], pos, pts, pos - start_pos[i] + 1, AVINDEX_KEYFRAME);

            start_pos[i]= asf_st->packet_pos + 1;

            if(pkt->stream_index == stream_index)

               break;

        }

    }

    *ppos= pos;

//printf("found keyframe at %Ld stream %d stamp:%Ld\n", *ppos, stream_index, pts);

    return pts;

}

static int asf_read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags)

{

    ASFContext *asf = s->priv_data;

    if (asf->packet_size <= 0)

        return -1;

    if(av_seek_frame_binary(s, stream_index, pts, flags)<0)

        return -1;

    asf_reset_header(s);

    return 0;

}

static AVInputFormat asf_iformat = {

    "asf",

    "asf format",

    sizeof(ASFContext),

    asf_probe,

    asf_read_header,

    asf_read_packet,

    asf_read_close,

    asf_read_seek,

    asf_read_pts,

};

#ifdef CONFIG_MUXERS

    extern AVOutputFormat asf_oformat;

    extern AVOutputFormat asf_stream_oformat;

#endif //CONFIG_MUXERS

int asf_init(void)

{

    av_register_input_format(&asf_iformat);

#ifdef CONFIG_MUXERS

    av_register_output_format(&asf_oformat);

    av_register_output_format(&asf_stream_oformat);

#endif //CONFIG_MUXERS

    return 0;

}