/*

  * ASF compatible demuxer

  * 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 <inttypes.h>
 

 #include "libavutil/attributes.h"

 #include "libavutil/avassert.h"

 #include "libavutil/avstring.h"

 #include "libavutil/bswap.h"

 #include "libavutil/common.h"

 #include "libavutil/dict.h"

 #include "libavutil/internal.h"

 #include "libavutil/mathematics.h"

 #include "libavutil/opt.h"

 #include "avformat.h"

 #include "avio_internal.h"

 #include "avlanguage.h"

 #include "id3v2.h"

 #include "internal.h"

 #include "riff.h"

 #include "asf.h"

 #include "asfcrypt.h"

 typedef struct ASFPayload {
     uint8_t type;
     uint16_t size;
 } ASFPayload;

 
 typedef struct ASFStream {

     int num;
     unsigned char seq;
     /* use for reading */
     AVPacket pkt;
     int frag_offset;
     int packet_obj_size;
     int timestamp;
     int64_t duration;
     int skip_to_key;
     int pkt_clean;

     int ds_span;                /* descrambling  */
     int ds_packet_size;
     int ds_chunk_size;

     int64_t packet_pos;

     uint16_t stream_language_index;

     int      palette_changed;
     uint32_t palette[256];

     int payload_ext_ct;
     ASFPayload payload[8];
 } ASFStream;

 typedef struct ASFContext {

     const AVClass *class;

     int asfid2avid[128];                 ///< conversion table from asf ID 2 AVStream ID
     ASFStream streams[128];              ///< it's max number and it's not that big
     uint32_t stream_bitrates[128];       ///< max number of streams, bitrate for each (for streaming)

     AVRational dar[128];

     char stream_languages[128][6];       ///< max number of streams, language for each (RFC1766, e.g. en-US)
     /* non streamed additonnal info */
     /* packet filling */
     int packet_size_left;
     /* only for reading */
     uint64_t data_offset;                ///< beginning of the first data packet
     uint64_t data_object_offset;         ///< data object offset (excl. GUID & size)
     uint64_t data_object_size;           ///< size of the data object
     int index_read;
 
     ASFMainHeader hdr;
 
     int packet_flags;
     int packet_property;
     int packet_timestamp;
     int packet_segsizetype;
     int packet_segments;
     int packet_seq;
     int packet_replic_size;
     int packet_key_frame;
     int packet_padsize;
     unsigned int packet_frag_offset;
     unsigned int packet_frag_size;
     int64_t packet_frag_timestamp;

     int ts_is_pts;

     int packet_multi_size;
     int packet_time_delta;
     int packet_time_start;
     int64_t packet_pos;
 
     int stream_index;
 

     ASFStream *asf_st;                   ///< currently decoded stream

 
     int no_resync_search;

     int export_xmp;

 
     int uses_std_ecc;

 } ASFContext;
 

 static const AVOption options[] = {

     { "no_resync_search", "Don't try to resynchronize by looking for a certain optional start code", offsetof(ASFContext, no_resync_search), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_DECODING_PARAM },

     { "export_xmp", "Export full XMP metadata", offsetof(ASFContext, export_xmp), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_DECODING_PARAM },

     { NULL },
 };
 
 static const AVClass asf_class = {
     .class_name = "asf demuxer",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };
 

 #undef NDEBUG
 #include <assert.h>
 

 #define ASF_MAX_STREAMS 127

 #define FRAME_HEADER_SIZE 6
 // Fix Me! FRAME_HEADER_SIZE may be different.
 // (7 is known to be too large for GipsyGuitar.wmv)

 #ifdef DEBUG

 static const ff_asf_guid stream_bitrate_guid = { /* (http://get.to/sdp) */

     0xce, 0x75, 0xf8, 0x7b, 0x8d, 0x46, 0xd1, 0x11, 0x8d, 0x82, 0x00, 0x60, 0x97, 0xc9, 0xa2, 0xb2
 };

 #define PRINT_IF_GUID(g, cmp) \
     if (!ff_guidcmp(g, &cmp)) \

         av_log(NULL, AV_LOG_TRACE, "(GUID: %s) ", # cmp)

 static void print_guid(ff_asf_guid *g)

 {
     int i;

     PRINT_IF_GUID(g, ff_asf_header);
     else PRINT_IF_GUID(g, ff_asf_file_header);
     else PRINT_IF_GUID(g, ff_asf_stream_header);
     else PRINT_IF_GUID(g, ff_asf_audio_stream);
     else PRINT_IF_GUID(g, ff_asf_audio_conceal_none);
     else PRINT_IF_GUID(g, ff_asf_video_stream);
     else PRINT_IF_GUID(g, ff_asf_video_conceal_none);
     else PRINT_IF_GUID(g, ff_asf_command_stream);
     else PRINT_IF_GUID(g, ff_asf_comment_header);
     else PRINT_IF_GUID(g, ff_asf_codec_comment_header);
     else PRINT_IF_GUID(g, ff_asf_codec_comment1_header);
     else PRINT_IF_GUID(g, ff_asf_data_header);

     else PRINT_IF_GUID(g, ff_asf_simple_index_header);

     else PRINT_IF_GUID(g, ff_asf_head1_guid);
     else PRINT_IF_GUID(g, ff_asf_head2_guid);
     else PRINT_IF_GUID(g, ff_asf_my_guid);
     else PRINT_IF_GUID(g, ff_asf_ext_stream_header);
     else PRINT_IF_GUID(g, ff_asf_extended_content_header);
     else PRINT_IF_GUID(g, ff_asf_ext_stream_embed_stream_header);
     else PRINT_IF_GUID(g, ff_asf_ext_stream_audio_stream);
     else PRINT_IF_GUID(g, ff_asf_metadata_header);

     else PRINT_IF_GUID(g, ff_asf_metadata_library_header);

     else PRINT_IF_GUID(g, ff_asf_marker_header);

     else PRINT_IF_GUID(g, stream_bitrate_guid);

     else PRINT_IF_GUID(g, ff_asf_language_guid);

     else

         av_log(NULL, AV_LOG_TRACE, "(GUID: unknown) ");

     for (i = 0; i < 16; i++)

         av_log(NULL, AV_LOG_TRACE, " 0x%02x,", (*g)[i]);
     av_log(NULL, AV_LOG_TRACE, "}\n");

 }

 #undef PRINT_IF_GUID

 #else

 #define print_guid(g) while(0)

 #endif
 

 static int asf_probe(AVProbeData *pd)
 {
     /* check file header */

     if (!ff_guidcmp(pd->buf, &ff_asf_header))

         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 

 /* size of type 2 (BOOL) is 32bit for "Extended Content Description Object"
  * but 16 bit for "Metadata Object" and "Metadata Library Object" */
 static int get_value(AVIOContext *pb, int type, int type2_size)

 {
     switch (type) {
     case 2:

         return (type2_size == 32) ? avio_rl32(pb) : avio_rl16(pb);

     case 3:
         return avio_rl32(pb);
     case 4:
         return avio_rl64(pb);
     case 5:
         return avio_rl16(pb);
     default:
         return INT_MIN;

     }
 }
 

 /* MSDN claims that this should be "compatible with the ID3 frame, APIC",
  * but in reality this is only loosely similar */
 static int asf_read_picture(AVFormatContext *s, int len)
 {

     AVPacket pkt          = { 0 };

     const CodecMime *mime = ff_id3v2_mime_tags;

     enum  AVCodecID id    = AV_CODEC_ID_NONE;

     char mimetype[64];
     uint8_t  *desc = NULL;
     AVStream   *st = NULL;
     int ret, type, picsize, desc_len;
 
     /* type + picsize + mime + desc */
     if (len < 1 + 4 + 2 + 2) {
         av_log(s, AV_LOG_ERROR, "Invalid attached picture size: %d.\n", len);
         return AVERROR_INVALIDDATA;
     }
 
     /* picture type */
     type = avio_r8(s->pb);
     len--;
     if (type >= FF_ARRAY_ELEMS(ff_id3v2_picture_types) || type < 0) {
         av_log(s, AV_LOG_WARNING, "Unknown attached picture type: %d.\n", type);
         type = 0;
     }
 
     /* picture data size */
     picsize = avio_rl32(s->pb);

     len    -= 4;

 
     /* picture MIME type */
     len -= avio_get_str16le(s->pb, len, mimetype, sizeof(mimetype));

     while (mime->id != AV_CODEC_ID_NONE) {

         if (!strncmp(mime->str, mimetype, sizeof(mimetype))) {
             id = mime->id;
             break;
         }
         mime++;
     }

     if (id == AV_CODEC_ID_NONE) {

         av_log(s, AV_LOG_ERROR, "Unknown attached picture mimetype: %s.\n",
                mimetype);
         return 0;
     }
 
     if (picsize >= len) {
         av_log(s, AV_LOG_ERROR, "Invalid attached picture data size: %d >= %d.\n",
                picsize, len);
         return AVERROR_INVALIDDATA;
     }
 
     /* picture description */
     desc_len = (len - picsize) * 2 + 1;
     desc     = av_malloc(desc_len);
     if (!desc)
         return AVERROR(ENOMEM);
     len -= avio_get_str16le(s->pb, len - picsize, desc, desc_len);
 
     ret = av_get_packet(s->pb, &pkt, picsize);
     if (ret < 0)
         goto fail;
 

     st  = avformat_new_stream(s, NULL);

     if (!st) {

         ret = AVERROR(ENOMEM);
         goto fail;
     }

     st->disposition              |= AV_DISPOSITION_ATTACHED_PIC;
     st->codec->codec_type         = AVMEDIA_TYPE_VIDEO;
     st->codec->codec_id           = id;
     st->attached_pic              = pkt;

     st->attached_pic.stream_index = st->index;

     st->attached_pic.flags       |= AV_PKT_FLAG_KEY;

 
     if (*desc)
         av_dict_set(&st->metadata, "title", desc, AV_DICT_DONT_STRDUP_VAL);
     else
         av_freep(&desc);
 
     av_dict_set(&st->metadata, "comment", ff_id3v2_picture_types[type], 0);
 
     return 0;
 
 fail:
     av_freep(&desc);
     av_free_packet(&pkt);
     return ret;
 }
 

 static void get_id3_tag(AVFormatContext *s, int len)
 {
     ID3v2ExtraMeta *id3v2_extra_meta = NULL;
 

     ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta, len);

     if (id3v2_extra_meta)
         ff_id3v2_parse_apic(s, &id3v2_extra_meta);
     ff_id3v2_free_extra_meta(&id3v2_extra_meta);
 }
 

 static void get_tag(AVFormatContext *s, const char *key, int type, int len, int type2_size)

 {

     ASFContext *asf = s->priv_data;
     char *value = NULL;

     int64_t off = avio_tell(s->pb);

 #define LEN 22

     if ((unsigned)len >= (UINT_MAX - LEN) / 2)

         return;
 

     if (!asf->export_xmp && !strncmp(key, "xmp", 3))
         goto finish;
 

     value = av_malloc(2 * len + LEN);

     if (!value)

         goto finish;

     switch (type) {
     case ASF_UNICODE:

         avio_get_str16le(s->pb, len, value, 2 * len + 1);

         break;
     case -1: // ASCI

         avio_read(s->pb, value, len);

         value[len]=0;

         break;
     case ASF_BYTE_ARRAY:

         if (!strcmp(key, "WM/Picture")) { // handle cover art
             asf_read_picture(s, len);
         } else if (!strcmp(key, "ID3")) { // handle ID3 tag
             get_id3_tag(s, len);
         } else {
             av_log(s, AV_LOG_VERBOSE, "Unsupported byte array in tag %s.\n", key);
         }
         goto finish;

     case ASF_BOOL:
     case ASF_DWORD:
     case ASF_QWORD:
     case ASF_WORD: {

         uint64_t num = get_value(s->pb, type, type2_size);

         snprintf(value, LEN, "%"PRIu64, num);

         break;
     }
     case ASF_GUID:

         av_log(s, AV_LOG_DEBUG, "Unsupported GUID value in tag %s.\n", key);
         goto finish;

     default:

         av_log(s, AV_LOG_DEBUG,
                "Unsupported value type %d in tag %s.\n", type, key);

         goto finish;

     }

     if (*value)

         av_dict_set(&s->metadata, key, value, 0);

 finish:

     av_freep(&value);

     avio_seek(s->pb, off + len, SEEK_SET);

 }
 

 static int asf_read_file_properties(AVFormatContext *s, int64_t size)
 {
     ASFContext *asf = s->priv_data;

     AVIOContext *pb = s->pb;

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

     asf->hdr.file_size   = avio_rl64(pb);
     asf->hdr.create_time = avio_rl64(pb);

     avio_rl64(pb);                               /* number of packets */

     asf->hdr.play_time   = avio_rl64(pb);
     asf->hdr.send_time   = avio_rl64(pb);
     asf->hdr.preroll     = avio_rl32(pb);
     asf->hdr.ignore      = avio_rl32(pb);
     asf->hdr.flags       = avio_rl32(pb);
     asf->hdr.min_pktsize = avio_rl32(pb);
     asf->hdr.max_pktsize = avio_rl32(pb);
     if (asf->hdr.min_pktsize >= (1U << 29))

         return AVERROR_INVALIDDATA;

     asf->hdr.max_bitrate = avio_rl32(pb);
     s->packet_size       = asf->hdr.max_pktsize;

 
     return 0;
 }
 

 static int asf_read_stream_properties(AVFormatContext *s, int64_t size)
 {
     ASFContext *asf = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *st;
     ASFStream *asf_st;
     ff_asf_guid g;
     enum AVMediaType type;
     int type_specific_size, sizeX;
     unsigned int tag1;
     int64_t pos1, pos2, start_time;

     int test_for_ext_stream_audio, is_dvr_ms_audio = 0;

 
     if (s->nb_streams == ASF_MAX_STREAMS) {
         av_log(s, AV_LOG_ERROR, "too many streams\n");
         return AVERROR(EINVAL);
     }
 

     pos1 = avio_tell(pb);

     st = avformat_new_stream(s, NULL);

     if (!st)
         return AVERROR(ENOMEM);

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

     start_time     = asf->hdr.preroll;

     if (!(asf->hdr.flags & 0x01)) { // if we aren't streaming...

         int64_t fsize = avio_size(pb);

         if (fsize <= 0 || (int64_t)asf->hdr.file_size <= 0 ||

             20*FFABS(fsize - (int64_t)asf->hdr.file_size) < FFMIN(fsize, asf->hdr.file_size))

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

                        (10000000 / 1000) - start_time;

     }
     ff_get_guid(pb, &g);
 
     test_for_ext_stream_audio = 0;
     if (!ff_guidcmp(&g, &ff_asf_audio_stream)) {
         type = AVMEDIA_TYPE_AUDIO;
     } else if (!ff_guidcmp(&g, &ff_asf_video_stream)) {
         type = AVMEDIA_TYPE_VIDEO;
     } else if (!ff_guidcmp(&g, &ff_asf_jfif_media)) {

         type                = AVMEDIA_TYPE_VIDEO;

         st->codec->codec_id = AV_CODEC_ID_MJPEG;

     } else if (!ff_guidcmp(&g, &ff_asf_command_stream)) {
         type = AVMEDIA_TYPE_DATA;
     } else if (!ff_guidcmp(&g, &ff_asf_ext_stream_embed_stream_header)) {
         test_for_ext_stream_audio = 1;

         type                      = AVMEDIA_TYPE_UNKNOWN;

     } else {
         return -1;
     }
     ff_get_guid(pb, &g);

     avio_skip(pb, 8); /* total_size */

     type_specific_size = avio_rl32(pb);
     avio_rl32(pb);
     st->id = avio_rl16(pb) & 0x7f; /* stream id */

     // mapping of asf ID to AV stream ID;
     asf->asfid2avid[st->id] = s->nb_streams - 1;

     asf_st = &asf->streams[st->id];

     avio_rl32(pb);

 
     if (test_for_ext_stream_audio) {
         ff_get_guid(pb, &g);
         if (!ff_guidcmp(&g, &ff_asf_ext_stream_audio_stream)) {

             type            = AVMEDIA_TYPE_AUDIO;
             is_dvr_ms_audio = 1;

             ff_get_guid(pb, &g);

             avio_rl32(pb);
             avio_rl32(pb);
             avio_rl32(pb);

             ff_get_guid(pb, &g);

             avio_rl32(pb);

         }
     }
 
     st->codec->codec_type = type;
     if (type == AVMEDIA_TYPE_AUDIO) {

         int ret = ff_get_wav_header(s, pb, st->codec, type_specific_size, 0);

         if (ret < 0)
             return ret;

         if (is_dvr_ms_audio) {
             // codec_id and codec_tag are unreliable in dvr_ms
             // files. Set them later by probing stream.

             st->request_probe    = 1;

             st->codec->codec_tag = 0;
         }

         if (st->codec->codec_id == AV_CODEC_ID_AAC)

             st->need_parsing = AVSTREAM_PARSE_NONE;

         else

             st->need_parsing = AVSTREAM_PARSE_FULL;
         /* We have to init the frame size at some point .... */

         pos2 = avio_tell(pb);

         if (size >= (pos2 + 8 - pos1 + 24)) {

             asf_st->ds_span        = avio_r8(pb);

             asf_st->ds_packet_size = avio_rl16(pb);

             asf_st->ds_chunk_size  = avio_rl16(pb);
             avio_rl16(pb);  // ds_data_size
             avio_r8(pb);    // 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_packet_size % asf_st->ds_chunk_size)
                 asf_st->ds_span = 0;  // disable descrambling

         }
     } else if (type == AVMEDIA_TYPE_VIDEO &&

                size - (avio_tell(pb) - pos1 + 24) >= 51) {

         avio_rl32(pb);
         avio_rl32(pb);
         avio_r8(pb);
         avio_rl16(pb);        /* size */

         sizeX             = avio_rl32(pb); /* size */
         st->codec->width  = avio_rl32(pb);

         st->codec->height = avio_rl32(pb);

         /* not available for asf */

         avio_rl16(pb); /* panes */
         st->codec->bits_per_coded_sample = avio_rl16(pb); /* depth */

         tag1                             = avio_rl32(pb);

         avio_skip(pb, 20);

         if (sizeX > 40) {

             st->codec->extradata_size = ffio_limit(pb, sizeX - 40);

             st->codec->extradata      = av_mallocz(st->codec->extradata_size +

                                                    AV_INPUT_BUFFER_PADDING_SIZE);

             if (!st->codec->extradata)
                 return AVERROR(ENOMEM);

             avio_read(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 libavcodec */

         if (st->codec->extradata_size && (st->codec->bits_per_coded_sample <= 8)) {
 #if HAVE_BIGENDIAN

             int i;

             for (i = 0; i < FFMIN(st->codec->extradata_size, AVPALETTE_SIZE) / 4; i++)
                 asf_st->palette[i] = av_bswap32(((uint32_t *)st->codec->extradata)[i]);

 #else

             memcpy(asf_st->palette, st->codec->extradata,
                    FFMIN(st->codec->extradata_size, AVPALETTE_SIZE));

 #endif

             asf_st->palette_changed = 1;

         }
 
         st->codec->codec_tag = tag1;

         st->codec->codec_id  = ff_codec_get_id(ff_codec_bmp_tags, tag1);
         if (tag1 == MKTAG('D', 'V', 'R', ' ')) {

             st->need_parsing = AVSTREAM_PARSE_FULL;

             /* issue658 contains wrong w/h and MS even puts a fake seq header
              * with wrong w/h in extradata while a correct one is in the stream.
              * maximum lameness */
             st->codec->width      =

                 st->codec->height = 0;
             av_freep(&st->codec->extradata);

             st->codec->extradata_size = 0;

         }

         if (st->codec->codec_id == AV_CODEC_ID_H264)

             st->need_parsing = AVSTREAM_PARSE_FULL_ONCE;

         if (st->codec->codec_id == AV_CODEC_ID_MPEG4)
             st->need_parsing = AVSTREAM_PARSE_FULL_ONCE;

     }

     pos2 = avio_tell(pb);

     avio_skip(pb, size - (pos2 - pos1 + 24));

 
     return 0;
 }
 

 static int asf_read_ext_stream_properties(AVFormatContext *s, int64_t size)
 {
     ASFContext *asf = s->priv_data;

     AVIOContext *pb = s->pb;

     ff_asf_guid g;
     int ext_len, payload_ext_ct, stream_ct, i;

     uint32_t leak_rate, stream_num;

     unsigned int stream_languageid_index;
 

     avio_rl64(pb); // starttime
     avio_rl64(pb); // endtime
     leak_rate = avio_rl32(pb); // leak-datarate
     avio_rl32(pb); // bucket-datasize
     avio_rl32(pb); // init-bucket-fullness
     avio_rl32(pb); // alt-leak-datarate
     avio_rl32(pb); // alt-bucket-datasize
     avio_rl32(pb); // alt-init-bucket-fullness
     avio_rl32(pb); // max-object-size
     avio_rl32(pb); // flags (reliable,seekable,no_cleanpoints?,resend-live-cleanpoints, rest of bits reserved)
     stream_num = avio_rl16(pb); // stream-num
 
     stream_languageid_index = avio_rl16(pb); // stream-language-id-index

     if (stream_num < 128)
         asf->streams[stream_num].stream_language_index = stream_languageid_index;
 

     avio_rl64(pb); // avg frametime in 100ns units

     stream_ct      = avio_rl16(pb); // stream-name-count
     payload_ext_ct = avio_rl16(pb); // payload-extension-system-count

     if (stream_num < 128) {

         asf->stream_bitrates[stream_num] = leak_rate;

         asf->streams[stream_num].payload_ext_ct = 0;
     }

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

         avio_rl16(pb);
         ext_len = avio_rl16(pb);

         avio_skip(pb, ext_len);

     }
 

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

         int size;

         ff_get_guid(pb, &g);

         size = avio_rl16(pb);

         ext_len = avio_rl32(pb);

         avio_skip(pb, ext_len);

         if (stream_num < 128 && i < FF_ARRAY_ELEMS(asf->streams[stream_num].payload)) {
             ASFPayload *p = &asf->streams[stream_num].payload[i];
             p->type = g[0];
             p->size = size;
             av_log(s, AV_LOG_DEBUG, "Payload extension %x %d\n", g[0], p->size );
             asf->streams[stream_num].payload_ext_ct ++;
         }

     }
 
     return 0;
 }
 
 static int asf_read_content_desc(AVFormatContext *s, int64_t size)
 {

     AVIOContext *pb = s->pb;

     int len1, len2, len3, len4, len5;
 

     len1 = avio_rl16(pb);
     len2 = avio_rl16(pb);
     len3 = avio_rl16(pb);
     len4 = avio_rl16(pb);
     len5 = avio_rl16(pb);

     get_tag(s, "title", 0, len1, 32);
     get_tag(s, "author", 0, len2, 32);
     get_tag(s, "copyright", 0, len3, 32);
     get_tag(s, "comment", 0, len4, 32);

     avio_skip(pb, len5);

 
     return 0;
 }
 
 static int asf_read_ext_content_desc(AVFormatContext *s, int64_t size)
 {

     AVIOContext *pb = s->pb;

     ASFContext *asf = s->priv_data;
     int desc_count, i, ret;
 

     desc_count = avio_rl16(pb);

     for (i = 0; i < desc_count; i++) {
         int name_len, value_type, value_len;

         char name[1024];
 

         name_len = avio_rl16(pb);

         if (name_len % 2)   // must be even, broken lavf versions wrote len-1

             name_len += 1;
         if ((ret = avio_get_str16le(pb, name_len, name, sizeof(name))) < name_len)

             avio_skip(pb, name_len - ret);

         value_type = avio_rl16(pb);
         value_len  = avio_rl16(pb);

         if (!value_type && value_len % 2)

             value_len += 1;

         /* My sample has that stream set to 0 maybe that mean the container.
          * ASF stream count starts at 1. I am using 0 to the container value
          * since it's unused. */
         if (!strcmp(name, "AspectRatioX"))

             asf->dar[0].num = get_value(s->pb, value_type, 32);

         else if (!strcmp(name, "AspectRatioY"))

             asf->dar[0].den = get_value(s->pb, value_type, 32);

         else

             get_tag(s, name, value_type, value_len, 32);

     }
 
     return 0;
 }
 
 static int asf_read_language_list(AVFormatContext *s, int64_t size)
 {

     AVIOContext *pb = s->pb;

     ASFContext *asf = s->priv_data;
     int j, ret;

     int stream_count = avio_rl16(pb);

     for (j = 0; j < stream_count; j++) {

         char lang[6];

         unsigned int lang_len = avio_r8(pb);

         if ((ret = avio_get_str16le(pb, lang_len, lang,
                                     sizeof(lang))) < lang_len)

             avio_skip(pb, lang_len - ret);

         if (j < 128)

             av_strlcpy(asf->stream_languages[j], lang,
                        sizeof(*asf->stream_languages));

     }
 
     return 0;
 }
 
 static int asf_read_metadata(AVFormatContext *s, int64_t size)
 {

     AVIOContext *pb = s->pb;

     ASFContext *asf = s->priv_data;

     int n, stream_num, name_len_utf16, name_len_utf8, value_len;

     int ret, i;

     n = avio_rl16(pb);

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

         uint8_t *name;

         int value_type;

         avio_rl16(pb);  // lang_list_index
         stream_num = avio_rl16(pb);

         name_len_utf16 = avio_rl16(pb);

         value_type = avio_rl16(pb); /* value_type */

         value_len  = avio_rl32(pb);

         name_len_utf8 = 2*name_len_utf16 + 1;
         name          = av_malloc(name_len_utf8);
         if (!name)
             return AVERROR(ENOMEM);
 
         if ((ret = avio_get_str16le(pb, name_len_utf16, name, name_len_utf8)) < name_len_utf16)
             avio_skip(pb, name_len_utf16 - ret);

         av_log(s, AV_LOG_TRACE, "%d stream %d name_len %2d type %d len %4d <%s>\n",

                 i, stream_num, name_len_utf16, value_type, value_len, name);

 
         if (!strcmp(name, "AspectRatioX")){
             int aspect_x = get_value(s->pb, value_type, 16);
             if(stream_num < 128)
                 asf->dar[stream_num].num = aspect_x;
         } else if(!strcmp(name, "AspectRatioY")){
             int aspect_y = get_value(s->pb, value_type, 16);
             if(stream_num < 128)
                 asf->dar[stream_num].den = aspect_y;
         } else {
             get_tag(s, name, value_type, value_len, 16);

         }

         av_freep(&name);

     }
 
     return 0;
 }
 
 static int asf_read_marker(AVFormatContext *s, int64_t size)
 {

     AVIOContext *pb = s->pb;

     ASFContext *asf = s->priv_data;

     int i, count, name_len, ret;
     char name[1024];
 

     avio_rl64(pb);            // reserved 16 bytes
     avio_rl64(pb);            // ...
     count = avio_rl32(pb);    // markers count
     avio_rl16(pb);            // reserved 2 bytes
     name_len = avio_rl16(pb); // name length

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

         avio_r8(pb); // skip the name

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

         int64_t pres_time;
         int name_len;
 

         avio_rl64(pb);             // offset, 8 bytes
         pres_time = avio_rl64(pb); // presentation time

         pres_time -= asf->hdr.preroll * 10000;

         avio_rl16(pb);             // entry length
         avio_rl32(pb);             // send time
         avio_rl32(pb);             // flags
         name_len = avio_rl32(pb);  // name length

         if ((ret = avio_get_str16le(pb, name_len * 2, name,
                                     sizeof(name))) < name_len)

             avio_skip(pb, name_len - ret);

         avpriv_new_chapter(s, i, (AVRational) { 1, 10000000 }, pres_time,
                            AV_NOPTS_VALUE, name);

     }
 
     return 0;
 }
 

 static int asf_read_header(AVFormatContext *s)

 {

     ASFContext *asf = s->priv_data;

     ff_asf_guid g;

     AVIOContext *pb = s->pb;

     int i;

     int64_t gsize;

     ff_get_guid(pb, &g);
     if (ff_guidcmp(&g, &ff_asf_header))

         return AVERROR_INVALIDDATA;

     avio_rl64(pb);
     avio_rl32(pb);
     avio_r8(pb);
     avio_r8(pb);

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

 
     for (i = 0; i<128; i++)
         asf->streams[i].stream_language_index = 128; // invalid stream index means no language info
 

     for (;;) {
         uint64_t gpos = avio_tell(pb);

         int ret = 0;

         ff_get_guid(pb, &g);

         gsize = avio_rl64(pb);

         print_guid(&g);

         if (!ff_guidcmp(&g, &ff_asf_data_header)) {

             asf->data_object_offset = avio_tell(pb);

             /* If not streaming, gsize is not unlimited (how?),
              * and there is enough space in the file.. */
             if (!(asf->hdr.flags & 0x01) && gsize >= 100)

                 asf->data_object_size = gsize - 24;

             else

                 asf->data_object_size = (uint64_t)-1;
             break;
         }

         if (gsize < 24)

             return AVERROR_INVALIDDATA;

         if (!ff_guidcmp(&g, &ff_asf_file_header)) {

             ret = asf_read_file_properties(s, gsize);

         } else if (!ff_guidcmp(&g, &ff_asf_stream_header)) {

             ret = asf_read_stream_properties(s, gsize);

         } else if (!ff_guidcmp(&g, &ff_asf_comment_header)) {

             asf_read_content_desc(s, gsize);

         } else if (!ff_guidcmp(&g, &ff_asf_language_guid)) {

             asf_read_language_list(s, gsize);

         } else if (!ff_guidcmp(&g, &ff_asf_extended_content_header)) {

             asf_read_ext_content_desc(s, gsize);

         } else if (!ff_guidcmp(&g, &ff_asf_metadata_header)) {

             asf_read_metadata(s, gsize);

         } else if (!ff_guidcmp(&g, &ff_asf_metadata_library_header)) {
             asf_read_metadata(s, gsize);

         } else if (!ff_guidcmp(&g, &ff_asf_ext_stream_header)) {

             asf_read_ext_stream_properties(s, gsize);

 
             // there could be a optional stream properties object to follow
             // if so the next iteration will pick it up

             continue;

         } else if (!ff_guidcmp(&g, &ff_asf_head1_guid)) {
             ff_get_guid(pb, &g);

             avio_skip(pb, 6);

             continue;

         } else if (!ff_guidcmp(&g, &ff_asf_marker_header)) {

             asf_read_marker(s, gsize);

         } else if (avio_feof(pb)) {

             return AVERROR_EOF;

         } else {

             if (!s->keylen) {

                 if (!ff_guidcmp(&g, &ff_asf_content_encryption)) {

                     unsigned int len;
                     AVPacket pkt;

                     av_log(s, AV_LOG_WARNING,
                            "DRM protected stream detected, decoding will likely fail!\n");

                     len= avio_rl32(pb);
                     av_log(s, AV_LOG_DEBUG, "Secret data:\n");

 
                     if ((ret = av_get_packet(pb, &pkt, len)) < 0)
                         return ret;
                     av_hex_dump_log(s, AV_LOG_DEBUG, pkt.data, pkt.size);
                     av_free_packet(&pkt);

                     len= avio_rl32(pb);

                     get_tag(s, "ASF_Protection_Type", -1, len, 32);

                     len= avio_rl32(pb);

                     get_tag(s, "ASF_Key_ID", -1, len, 32);

                     len= avio_rl32(pb);

                     get_tag(s, "ASF_License_URL", -1, len, 32);

                 } else if (!ff_guidcmp(&g, &ff_asf_ext_content_encryption)) {

                     av_log(s, AV_LOG_WARNING,
                            "Ext DRM protected stream detected, decoding will likely fail!\n");

                     av_dict_set(&s->metadata, "encryption", "ASF Extended Content Encryption", 0);

                 } else if (!ff_guidcmp(&g, &ff_asf_digital_signature)) {

                     av_log(s, AV_LOG_INFO, "Digital signature detected!\n");

                 }
             }

         }

         if (ret < 0)
             return ret;
 

         if (avio_tell(pb) != gpos + gsize)
             av_log(s, AV_LOG_DEBUG,
                    "gpos mismatch our pos=%"PRIu64", end=%"PRId64"\n",
                    avio_tell(pb) - gpos, gsize);

         avio_seek(pb, gpos + gsize, SEEK_SET);

     }

     ff_get_guid(pb, &g);

     avio_rl64(pb);
     avio_r8(pb);
     avio_r8(pb);

     if (avio_feof(pb))

         return AVERROR_EOF;

     asf->data_offset      = avio_tell(pb);

     asf->packet_size_left = 0;
 

     for (i = 0; i < 128; i++) {
         int stream_num = asf->asfid2avid[i];
         if (stream_num >= 0) {

             AVStream *st = s->streams[stream_num];
             if (!st->codec->bit_rate)

                 st->codec->bit_rate = asf->stream_bitrates[i];

             if (asf->dar[i].num > 0 && asf->dar[i].den > 0) {

                 av_reduce(&st->sample_aspect_ratio.num,
                           &st->sample_aspect_ratio.den,

                           asf->dar[i].num, asf->dar[i].den, INT_MAX);

             } else if ((asf->dar[0].num > 0) && (asf->dar[0].den > 0) &&
                        // Use ASF container value if the stream doesn't set AR.
                        (st->codec->codec_type == AVMEDIA_TYPE_VIDEO))

                 av_reduce(&st->sample_aspect_ratio.num,
                           &st->sample_aspect_ratio.den,

                           asf->dar[0].num, asf->dar[0].den, INT_MAX);

             av_log(s, AV_LOG_TRACE, "i=%d, st->codec->codec_type:%d, asf->dar %d:%d sar=%d:%d\n",

                     i, st->codec->codec_type, asf->dar[i].num, asf->dar[i].den,
                     st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);

 
             // copy and convert language codes to the frontend
             if (asf->streams[i].stream_language_index < 128) {
                 const char *rfc1766 = asf->stream_languages[asf->streams[i].stream_language_index];
                 if (rfc1766 && strlen(rfc1766) > 1) {
                     const char primary_tag[3] = { rfc1766[0], rfc1766[1], '\0' }; // ignore country code if any

                     const char *iso6392       = av_convert_lang_to(primary_tag,
                                                                    AV_LANG_ISO639_2_BIBL);

                     if (iso6392)

                         av_dict_set(&st->metadata, "language", iso6392, 0);

                 }
             }

         }
     }
 

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

     return 0;
 }
 

 #define DO_2BITS(bits, var, defval)             \
     switch (bits & 3) {                         \
     case 3:                                     \
         var = avio_rl32(pb);                    \
         rsize += 4;                             \
         break;                                  \
     case 2:                                     \
         var = avio_rl16(pb);                    \
         rsize += 2;                             \
         break;                                  \
     case 1:                                     \
         var = avio_r8(pb);                      \
         rsize++;                                \
         break;                                  \
     default:                                    \
         var = defval;                           \
         break;                                  \

     }
 

 /**
  * Load a single ASF packet into the demuxer.
  * @param s demux context
  * @param pb context to read data from

  * @return 0 on success, <0 on error

  */

 static int asf_get_packet(AVFormatContext *s, AVIOContext *pb)

 {
     ASFContext *asf = s->priv_data;

     uint32_t packet_length, padsize;

     int rsize = 8;

     int c, d, e, off;
 

     if (asf->uses_std_ecc > 0) {

         // if we do not know packet size, allow skipping up to 32 kB
         off = 32768;
         if (asf->no_resync_search)
             off = 3;

 //         else if (s->packet_size > 0 && !asf->uses_std_ecc)
 //             off = (avio_tell(pb) - s->internal->data_offset) % s->packet_size + 3;

 
         c = d = e = -1;
         while (off-- > 0) {
             c = d;
             d = e;
             e = avio_r8(pb);
             if (c == 0x82 && !d && !e)
                 break;
         }

         if (c != 0x82) {
             /* This code allows handling of -EAGAIN at packet boundaries (i.e.
             * if the packet sync code above triggers -EAGAIN). This does not
             * imply complete -EAGAIN handling support at random positions in
             * the stream. */
             if (pb->error == AVERROR(EAGAIN))
                 return AVERROR(EAGAIN);

             if (!avio_feof(pb))

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

         }

         if ((c & 0x8f) == 0x82) {
             if (d || e) {
                 if (!avio_feof(pb))
                     av_log(s, AV_LOG_ERROR, "ff asf bad non zero\n");
                 return AVERROR_INVALIDDATA;
             }
             c      = avio_r8(pb);
             d      = avio_r8(pb);
             rsize += 3;
         } else if(!avio_feof(pb)) {
             avio_seek(pb, -1, SEEK_CUR); // FIXME
         }
     } else {
         c = avio_r8(pb);

         if (c & 0x80) {
             rsize ++;
             if (!(c & 0x60)) {
                 d = avio_r8(pb);
                 e = avio_r8(pb);
                 avio_seek(pb, (c & 0xF) - 2, SEEK_CUR);
                 rsize += c & 0xF;
             }
 
             if (c != 0x82)
                 avpriv_request_sample(s, "Invalid ECC byte\n");
 
             if (!asf->uses_std_ecc)
                 asf->uses_std_ecc =  (c == 0x82 && !d && !e) ? 1 : -1;
 
             c = avio_r8(pb);
         } else
             asf->uses_std_ecc =  -1;

         d = avio_r8(pb);

     }

     asf->packet_flags    = c;
     asf->packet_property = d;

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

     DO_2BITS(asf->packet_flags >> 1, padsize, 0); // sequence ignored
     DO_2BITS(asf->packet_flags >> 3, padsize, 0); // padding length
 

     // the following checks prevent overflows and infinite loops
     if (!packet_length || packet_length >= (1U << 29)) {
         av_log(s, AV_LOG_ERROR,

                "invalid packet_length %"PRIu32" at:%"PRId64"\n",

                packet_length, avio_tell(pb));

         return AVERROR_INVALIDDATA;

     }

     if (padsize >= packet_length) {
         av_log(s, AV_LOG_ERROR,

                "invalid padsize %"PRIu32" at:%"PRId64"\n", padsize, avio_tell(pb));

         return AVERROR_INVALIDDATA;

     }
 

     asf->packet_timestamp = avio_rl32(pb);
     avio_rl16(pb); /* duration */

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

 
     if (asf->packet_flags & 0x01) {

         asf->packet_segsizetype = avio_r8(pb);
         rsize++;

         asf->packet_segments = asf->packet_segsizetype & 0x3f;
     } else {

         asf->packet_segments    = 1;

         asf->packet_segsizetype = 0x80;
     }

     if (rsize > packet_length - padsize) {
         asf->packet_size_left = 0;
         av_log(s, AV_LOG_ERROR,

                "invalid packet header length %d for pktlen %"PRIu32"-%"PRIu32" at %"PRId64"\n",

                rsize, packet_length, padsize, avio_tell(pb));

         return AVERROR_INVALIDDATA;

     }

     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;

     av_log(s, AV_LOG_TRACE, "packet: size=%d padsize=%d  left=%d\n",

             s->packet_size, asf->packet_padsize, asf->packet_size_left);

     return 0;
 }
 

 /**
  *
  * @return <0 if error
  */

 static int asf_read_frame_header(AVFormatContext *s, AVIOContext *pb)
 {

     ASFContext *asf = s->priv_data;

     ASFStream *asfst;

     int rsize       = 1;
     int num         = avio_r8(pb);

     int i;

     int64_t ts0, ts1 av_unused;

 
     asf->packet_segments--;
     asf->packet_key_frame = num >> 7;

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

     asfst                 = &asf->streams[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);

     av_log(asf, AV_LOG_TRACE, "key:%d stream:%d seq:%d offset:%d replic_size:%d num:%X packet_property %X\n",

             asf->packet_key_frame, asf->stream_index, asf->packet_seq,

             asf->packet_frag_offset, asf->packet_replic_size, num, asf->packet_property);

     if (rsize+(int64_t)asf->packet_replic_size > asf->packet_size_left) {

         av_log(s, AV_LOG_ERROR, "packet_replic_size %d is invalid\n", asf->packet_replic_size);

         return AVERROR_INVALIDDATA;

     }

     if (asf->packet_replic_size >= 8) {

         int64_t end = avio_tell(pb) + asf->packet_replic_size;

         AVRational aspect;

         asfst->packet_obj_size = avio_rl32(pb);

         if (asfst->packet_obj_size >= (1 << 24) || asfst->packet_obj_size < 0) {

             av_log(s, AV_LOG_ERROR, "packet_obj_size %d invalid\n", asfst->packet_obj_size);

             asfst->packet_obj_size = 0;

             return AVERROR_INVALIDDATA;

         }

         asf->packet_frag_timestamp = avio_rl32(pb); // timestamp

         for (i = 0; i < asfst->payload_ext_ct; i++) {

             ASFPayload *p = &asfst->payload[i];
             int size = p->size;
             int64_t payend;

             if (size == 0xFFFF)

                 size = avio_rl16(pb);
             payend = avio_tell(pb) + size;
             if (payend > end) {
                 av_log(s, AV_LOG_ERROR, "too long payload\n");
                 break;
             }

             switch (p->type) {

             case 0x50:
 //              duration = avio_rl16(pb);
                 break;

             case 0x54:
                 aspect.num = avio_r8(pb);
                 aspect.den = avio_r8(pb);

                 if (aspect.num > 0 && aspect.den > 0 && asf->stream_index >= 0) {

                     s->streams[asf->stream_index]->sample_aspect_ratio = aspect;
                 }
                 break;

             case 0x2A:
                 avio_skip(pb, 8);

                 ts0 = avio_rl64(pb);
                 ts1 = avio_rl64(pb);
                 if (ts0!= -1) asf->packet_frag_timestamp = ts0/10000;
                 else          asf->packet_frag_timestamp = AV_NOPTS_VALUE;

                 asf->ts_is_pts = 1;

                 break;
             case 0x5B:
             case 0xB7:
             case 0xCC:
             case 0xC0:
             case 0xA0:
                 //unknown
                 break;
             }
             avio_seek(pb, payend, SEEK_SET);
         }
 
         avio_seek(pb, end, SEEK_SET);

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

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

         // multipacket - frag_offset is beginning 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 = avio_r8(pb);

         rsize++;

     } else if (asf->packet_replic_size != 0) {
         av_log(s, AV_LOG_ERROR, "unexpected packet_replic_size of %d\n",
                asf->packet_replic_size);

         return AVERROR_INVALIDDATA;

     }
     if (asf->packet_flags & 0x01) {
         DO_2BITS(asf->packet_segsizetype >> 6, asf->packet_frag_size, 0); // 0 is illegal

         if (rsize > asf->packet_size_left) {
             av_log(s, AV_LOG_ERROR, "packet_replic_size is invalid\n");

             return AVERROR_INVALIDDATA;

         } else if (asf->packet_frag_size > asf->packet_size_left - rsize) {

             if (asf->packet_frag_size > asf->packet_size_left - rsize + asf->packet_padsize) {

                 av_log(s, AV_LOG_ERROR, "packet_frag_size is invalid (%d>%d-%d+%d)\n",
                        asf->packet_frag_size, asf->packet_size_left, rsize, asf->packet_padsize);

                 return AVERROR_INVALIDDATA;

             } else {
                 int diff = asf->packet_frag_size - (asf->packet_size_left - rsize);
                 asf->packet_size_left += diff;
                 asf->packet_padsize   -= diff;
             }

         }

     } else {
         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)

             return AVERROR_INVALIDDATA;

     }
     asf->packet_size_left -= rsize;
 
     return 0;
 }
 

 /**
  * Parse data from individual ASF packets (which were previously loaded
  * with asf_get_packet()).
  * @param s demux context
  * @param pb context to read data from
  * @param pkt pointer to store packet data into

  * @return 0 if data was stored in pkt, <0 on error or 1 if more ASF

  *          packets need to be loaded (through asf_get_packet())
  */

 static int asf_parse_packet(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)

 {

     ASFContext *asf   = s->priv_data;

     ASFStream *asf_st = 0;
     for (;;) {

         int ret;

         if (avio_feof(pb))

             return AVERROR_EOF;

         if (asf->packet_size_left < FRAME_HEADER_SIZE ||
             asf->packet_segments < 1 && asf->packet_time_start == 0) {

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

             if (asf->packet_size_left && asf->packet_size_left < FRAME_HEADER_SIZE)
                 av_log(s, AV_LOG_WARNING, "Skip due to FRAME_HEADER_SIZE\n");
 

             assert(ret >= 0);

             /* fail safe */

             avio_skip(pb, ret);

             asf->packet_pos = avio_tell(pb);

             if (asf->data_object_size != (uint64_t)-1 &&
                 (asf->packet_pos - asf->data_object_offset >= asf->data_object_size))

                 return AVERROR_EOF;  /* Do not exceed the size of the data object */

             return 1;

         }
         if (asf->packet_time_start == 0) {

             if (asf_read_frame_header(s, pb) < 0) {

                 asf->packet_time_start = asf->packet_segments = 0;

                 continue;

             }

             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->streams[s->streams[asf->stream_index]->id].skip_to_key))) {

                 asf->packet_time_start = 0;

                 /* unhandled packet (should not happen) */

                 avio_skip(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 (unknown stream)\n",
                            asf->packet_frag_size);

                 continue;

             }

             asf->asf_st = &asf->streams[s->streams[asf->stream_index]->id];

             if (!asf->packet_frag_offset)
                 asf->asf_st->skip_to_key = 0;

         }
         asf_st = asf->asf_st;

         av_assert0(asf_st);

         if (!asf_st->frag_offset && asf->packet_frag_offset) {

             av_log(s, AV_LOG_TRACE, "skipping asf data pkt with fragment offset for "

                     "stream:%d, expected:%d but got %d from pkt)\n",
                     asf->stream_index, asf_st->frag_offset,
                     asf->packet_frag_offset);
             avio_skip(pb, 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 beginning timestamp

             asf->packet_frag_timestamp = asf->packet_time_start;

             asf->packet_time_start    += asf->packet_time_delta;

             asf_st->packet_obj_size    = asf->packet_frag_size = avio_r8(pb);

             asf->packet_size_left--;

             asf->packet_multi_size--;

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

                 asf->packet_time_start = 0;

                 avio_skip(pb, asf->packet_multi_size);

                 asf->packet_size_left -= asf->packet_multi_size;

                 continue;

             }

             asf->packet_multi_size -= asf_st->packet_obj_size;

         }

         if (asf_st->pkt.size != asf_st->packet_obj_size ||

             // FIXME is this condition sufficient?

             asf_st->frag_offset + asf->packet_frag_size > asf_st->pkt.size) {

             int ret;
 

             if (asf_st->pkt.data) {

                 av_log(s, AV_LOG_INFO,
                        "freeing incomplete packet size %d, new %d\n",

                        asf_st->pkt.size, asf_st->packet_obj_size);

                 asf_st->frag_offset = 0;
                 av_free_packet(&asf_st->pkt);
             }

             /* new packet */

             if ((ret = av_new_packet(&asf_st->pkt, asf_st->packet_obj_size)) < 0)
                 return ret;

             asf_st->seq              = asf->packet_seq;

             if (asf->ts_is_pts) {
                 asf_st->pkt.pts          = asf->packet_frag_timestamp - asf->hdr.preroll;
             } else
                 asf_st->pkt.dts          = asf->packet_frag_timestamp - asf->hdr.preroll;

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

             asf_st->pkt.pos          = asf_st->packet_pos = asf->packet_pos;

             asf_st->pkt_clean        = 0;

             if (asf_st->pkt.data && asf_st->palette_changed) {
                 uint8_t *pal;

                 pal = av_packet_new_side_data(&asf_st->pkt, AV_PKT_DATA_PALETTE,

                                               AVPALETTE_SIZE);
                 if (!pal) {
                     av_log(s, AV_LOG_ERROR, "Cannot append palette to packet\n");
                 } else {
                     memcpy(pal, asf_st->palette, AVPALETTE_SIZE);
                     asf_st->palette_changed = 0;
                 }
             }

             av_log(asf, AV_LOG_TRACE, "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 & AV_PKT_FLAG_KEY,
                     s->streams[asf->stream_index]->codec->codec_type == AVMEDIA_TYPE_AUDIO,

                     asf_st->packet_obj_size);

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

                 asf->packet_key_frame = 1;
             if (asf->packet_key_frame)

                 asf_st->pkt.flags |= AV_PKT_FLAG_KEY;

         }
 
         /* read data */

         av_log(asf, AV_LOG_TRACE, "READ PACKET s:%d  os:%d  o:%d,%d  l:%d   DATA:%p\n",

                 s->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;

         if (asf->packet_frag_offset >= asf_st->pkt.size ||
             asf->packet_frag_size > asf_st->pkt.size - asf->packet_frag_offset) {

             av_log(s, AV_LOG_ERROR,
                    "packet fragment position invalid %u,%u not in %u\n",
                    asf->packet_frag_offset, asf->packet_frag_size,
                    asf_st->pkt.size);

             continue;
         }
 

         if (asf->packet_frag_offset != asf_st->frag_offset && !asf_st->pkt_clean) {
             memset(asf_st->pkt.data + asf_st->frag_offset, 0, asf_st->pkt.size - asf_st->frag_offset);
             asf_st->pkt_clean = 1;
         }
 

         ret = avio_read(pb, asf_st->pkt.data + asf->packet_frag_offset,

                         asf->packet_frag_size);

         if (ret != asf->packet_frag_size) {
             if (ret < 0 || asf->packet_frag_offset + ret == 0)
                 return ret < 0 ? ret : AVERROR_EOF;

             if (asf_st->ds_span > 1) {
                 // scrambling, we can either drop it completely or fill the remainder
                 // TODO: should we fill the whole packet instead of just the current
                 // fragment?
                 memset(asf_st->pkt.data + asf->packet_frag_offset + ret, 0,
                        asf->packet_frag_size - ret);
                 ret = asf->packet_frag_size;

             } else {

                 // no scrambling, so we can return partial packets
                 av_shrink_packet(&asf_st->pkt, asf->packet_frag_offset + ret);

             }

         }

         if (s->key && s->keylen == 20)
             ff_asfcrypt_dec(s->key, asf_st->pkt.data + asf->packet_frag_offset,

                             ret);
         asf_st->frag_offset += ret;

         /* test if whole packet is read */
         if (asf_st->frag_offset == asf_st->pkt.size) {

             // workaround for macroshit radio DVR-MS files

             if (s->streams[asf->stream_index]->codec->codec_id == AV_CODEC_ID_MPEG2VIDEO &&
                 asf_st->pkt.size > 100) {

                 int i;

                 for (i = 0; i < asf_st->pkt.size && !asf_st->pkt.data[i]; i++)
                     ;

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

                     av_log(s, AV_LOG_DEBUG, "discarding ms fart\n");
                     asf_st->frag_offset = 0;
                     av_free_packet(&asf_st->pkt);
                     continue;
                 }
             }
 

             /* return packet */
             if (asf_st->ds_span > 1) {

                 if (asf_st->pkt.size != asf_st->ds_packet_size * asf_st->ds_span) {
                     av_log(s, AV_LOG_ERROR,
                            "pkt.size != ds_packet_size * ds_span (%d %d %d)\n",
                            asf_st->pkt.size, asf_st->ds_packet_size,
                            asf_st->ds_span);

                 } else {
                     /* packet descrambling */

                     AVBufferRef *buf = av_buffer_alloc(asf_st->pkt.size +

                                                        AV_INPUT_BUFFER_PADDING_SIZE);

                     if (buf) {
                         uint8_t *newdata = buf->data;

                         int offset = 0;

                         memset(newdata + asf_st->pkt.size, 0,

                                AV_INPUT_BUFFER_PADDING_SIZE);

                         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;
                             assert(offset + asf_st->ds_chunk_size <= asf_st->pkt.size);

                             assert(idx + 1 <= asf_st->pkt.size / asf_st->ds_chunk_size);

                             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_buffer_unref(&asf_st->pkt.buf);
                         asf_st->pkt.buf  = buf;
                         asf_st->pkt.data = buf->data;

                     }
                 }
             }

             asf_st->frag_offset         = 0;
             *pkt                        = asf_st->pkt;

 #if FF_API_DESTRUCT_PACKET

 FF_DISABLE_DEPRECATION_WARNINGS

             asf_st->pkt.destruct        = NULL;

 FF_ENABLE_DEPRECATION_WARNINGS

 #endif
             asf_st->pkt.buf             = 0;

             asf_st->pkt.size            = 0;
             asf_st->pkt.data            = 0;

             asf_st->pkt.side_data_elems = 0;

             asf_st->pkt.side_data       = NULL;

             break; // packet completed
         }

     }
     return 0;
 }
 

 static int asf_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     ASFContext *asf = s->priv_data;
 
     for (;;) {
         int ret;
 
         /* parse cached packets, if any */

         if ((ret = asf_parse_packet(s, s->pb, pkt)) <= 0)

             return ret;

         if ((ret = asf_get_packet(s, s->pb)) < 0)

             assert(asf->packet_size_left < FRAME_HEADER_SIZE ||
                    asf->packet_segments < 1);

         asf->packet_time_start = 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_size_left      = 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_time_delta     = 0;
     asf->packet_time_start     = 0;

     for (i = 0; i < 128; i++) {
         asf_st = &asf->streams[i];

         av_free_packet(&asf_st->pkt);

         asf_st->packet_obj_size = 0;

         asf_st->frag_offset = 0;
         asf_st->seq         = 0;

     }

     asf->asf_st = NULL;

 }
 

 static void skip_to_key(AVFormatContext *s)
 {
     ASFContext *asf = s->priv_data;
     int i;
 
     for (i = 0; i < 128; i++) {
         int j = asf->asfid2avid[i];
         ASFStream *asf_st = &asf->streams[i];
         if (j < 0 || s->streams[j]->codec->codec_type != AVMEDIA_TYPE_VIDEO)
             continue;
 
         asf_st->skip_to_key = 1;
     }
 }
 

 static int asf_read_close(AVFormatContext *s)
 {
     asf_reset_header(s);

     return 0;
 }
 

 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[ASF_MAX_STREAMS];

     for (i = 0; i < s->nb_streams; i++)
         start_pos[i] = pos;

     if (s->packet_size > 0)

         pos = (pos + s->packet_size - 1 - s->internal->data_offset) /

               s->packet_size * s->packet_size +

               s->internal->data_offset;

     *ppos = pos;

     if (avio_seek(s->pb, pos, SEEK_SET) < 0)
         return AV_NOPTS_VALUE;

     ff_read_frame_flush(s);

     asf_reset_header(s);

     for (;;) {

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

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

             return AV_NOPTS_VALUE;

         }

         pts = pkt->dts;

 
         av_free_packet(pkt);

         if (pkt->flags & AV_PKT_FLAG_KEY) {
             i = pkt->stream_index;

             asf_st = &asf->streams[s->streams[i]->id];

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

             pos = asf_st->packet_pos;

             av_assert1(pkt->pos == asf_st->packet_pos);

             av_add_index_entry(s->streams[i], pos, pts, pkt->size,
                                pos - start_pos[i] + 1, AVINDEX_KEYFRAME);
             start_pos[i] = asf_st->packet_pos + 1;

             if (pkt->stream_index == stream_index)
                 break;

         }
     }
 

     *ppos = pos;

     return pts;

 }
 

 static int asf_build_simple_index(AVFormatContext *s, int stream_index)

 {

     ff_asf_guid g;

     ASFContext *asf     = s->priv_data;
     int64_t current_pos = avio_tell(s->pb);

     int64_t ret;

     if((ret = avio_seek(s->pb, asf->data_object_offset + asf->data_object_size, SEEK_SET)) < 0) {
         return ret;

     }

     if ((ret = ff_get_guid(s->pb, &g)) < 0)
         goto end;

 
     /* the data object can be followed by other top-level objects,

      * skip them until the simple index object is reached */

     while (ff_guidcmp(&g, &ff_asf_simple_index_header)) {

         int64_t gsize = avio_rl64(s->pb);

         if (gsize < 24 || avio_feof(s->pb)) {

             goto end;

         }

         avio_skip(s->pb, gsize - 24);

         if ((ret = ff_get_guid(s->pb, &g)) < 0)
             goto end;

     }
 
     {

         int64_t itime, last_pos = -1;

         int pct, ict;

         int i;

         int64_t av_unused gsize = avio_rl64(s->pb);

         if ((ret = ff_get_guid(s->pb, &g)) < 0)
             goto end;

         itime = avio_rl64(s->pb);
         pct   = avio_rl32(s->pb);
         ict   = avio_rl32(s->pb);
         av_log(s, AV_LOG_DEBUG,
                "itime:0x%"PRIx64", pct:%d, ict:%d\n", itime, pct, ict);
 
         for (i = 0; i < ict; i++) {
             int pktnum        = avio_rl32(s->pb);
             int pktct         = avio_rl16(s->pb);

             int64_t pos       = s->internal->data_offset + s->packet_size * (int64_t)pktnum;

             int64_t index_pts = FFMAX(av_rescale(itime, i, 10000) - asf->hdr.preroll, 0);
 
             if (pos != last_pos) {
                 av_log(s, AV_LOG_DEBUG, "pktnum:%d, pktct:%d  pts: %"PRId64"\n",
                        pktnum, pktct, index_pts);
                 av_add_index_entry(s->streams[stream_index], pos, index_pts,
                                    s->packet_size, 0, AVINDEX_KEYFRAME);
                 last_pos = pos;

             }

         }

         asf->index_read = ict > 1;

     }

 end:

 //     if (avio_feof(s->pb)) {

 //         ret = 0;
 //     }

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

     return ret;

 }
 

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

 {

     ASFContext *asf = s->priv_data;

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

     int ret = 0;

     if (s->packet_size <= 0)

         return -1;
 

     /* Try using the protocol's read_seek if available */

     if (s->pb) {

         int64_t ret = avio_seek_time(s->pb, stream_index, pts, flags);

         if (ret >= 0)

             asf_reset_header(s);

         if (ret != AVERROR(ENOSYS))

             return ret;

     }
 

     /* explicitly handle the case of seeking to 0 */
     if (!pts) {
         asf_reset_header(s);

         avio_seek(s->pb, s->internal->data_offset, SEEK_SET);

         return 0;
     }
 

     if (!asf->index_read) {

         ret = asf_build_simple_index(s, stream_index);

         if (ret < 0)
             asf->index_read = -1;
     }

     if (asf->index_read > 0 && st->index_entries) {

         int index = av_index_search_timestamp(st, pts, flags);

         if (index >= 0) {

             /* find the position */

             uint64_t pos = st->index_entries[index].pos;

             /* do the seek */
             av_log(s, AV_LOG_DEBUG, "SEEKTO: %"PRId64"\n", pos);

             if(avio_seek(s->pb, pos, SEEK_SET) < 0)
                 return -1;

             asf_reset_header(s);

             skip_to_key(s);

             return 0;

         }

     }

     /* no index or seeking by index failed */

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

         return -1;

     asf_reset_header(s);

     skip_to_key(s);

     return 0;

 }
 

 AVInputFormat ff_asf_demuxer = {

     .name           = "asf",

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

     .priv_data_size = sizeof(ASFContext),
     .read_probe     = asf_probe,
     .read_header    = asf_read_header,
     .read_packet    = asf_read_packet,
     .read_close     = asf_read_close,
     .read_seek      = asf_read_seek,
     .read_timestamp = asf_read_pts,

     .flags          = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH,

     .priv_class     = &asf_class,

 };