/*
  * "Real" 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 "libavutil/avstring.h"

 #include "libavutil/intreadwrite.h"

 #include "libavutil/dict.h"

 #include "avformat.h"

 #include "internal.h"

 #include "riff.h"

 #include "rm.h"

 #define DEINT_ID_GENR MKTAG('g', 'e', 'n', 'r') ///< interleaving for Cooker/Atrac
 #define DEINT_ID_INT0 MKTAG('I', 'n', 't', '0') ///< no interleaving needed
 #define DEINT_ID_INT4 MKTAG('I', 'n', 't', '4') ///< interleaving for 28.8
 #define DEINT_ID_SIPR MKTAG('s', 'i', 'p', 'r') ///< interleaving for Sipro
 #define DEINT_ID_VBRF MKTAG('v', 'b', 'r', 'f') ///< VBR case for AAC
 #define DEINT_ID_VBRS MKTAG('v', 'b', 'r', 's') ///< VBR case for AAC
 

 struct RMStream {

     AVPacket pkt;      ///< place to store merged video frame / reordered audio data

     int videobufsize;  ///< current assembled frame size
     int videobufpos;   ///< position for the next slice in the video buffer
     int curpic_num;    ///< picture number of current frame
     int cur_slice, slices;
     int64_t pktpos;    ///< first slice position in file
     /// Audio descrambling matrix parameters
     int64_t audiotimestamp; ///< Audio packet timestamp
     int sub_packet_cnt; // Subpacket counter, used while reading
     int sub_packet_size, sub_packet_h, coded_framesize; ///< Descrambling parameters from container

     int audio_framesize; /// Audio frame size from container
     int sub_packet_lengths[16]; /// Length of each subpacket

     int32_t deint_id;  ///< deinterleaver used in audio stream

 };
 
 typedef struct {
     int nb_packets;
     int old_format;
     int current_stream;
     int remaining_len;

     int audio_stream_num; ///< Stream number for audio packets
     int audio_pkt_cnt; ///< Output packet counter
 } RMDemuxContext;

 static const unsigned char sipr_swaps[38][2] = {
     {  0, 63 }, {  1, 22 }, {  2, 44 }, {  3, 90 },
     {  5, 81 }, {  7, 31 }, {  8, 86 }, {  9, 58 },
     { 10, 36 }, { 12, 68 }, { 13, 39 }, { 14, 73 },
     { 15, 53 }, { 16, 69 }, { 17, 57 }, { 19, 88 },
     { 20, 34 }, { 21, 71 }, { 24, 46 }, { 25, 94 },
     { 26, 54 }, { 28, 75 }, { 29, 50 }, { 32, 70 },
     { 33, 92 }, { 35, 74 }, { 38, 85 }, { 40, 56 },
     { 42, 87 }, { 43, 65 }, { 45, 59 }, { 48, 79 },
     { 49, 93 }, { 51, 89 }, { 55, 95 }, { 61, 76 },
     { 67, 83 }, { 77, 80 }
 };
 

 const unsigned char ff_sipr_subpk_size[4] = { 29, 19, 37, 20 };

 static inline void get_strl(AVIOContext *pb, char *buf, int buf_size, int len)

 {

     int i;

     char *q, r;

 
     q = buf;
     for(i=0;i<len;i++) {

         r = avio_r8(pb);

         if (i < buf_size - 1)

             *q++ = r;

     }

     if (buf_size > 0) *q = '\0';

 }
 

 static void get_str8(AVIOContext *pb, char *buf, int buf_size)

 {

     get_strl(pb, buf, buf_size, avio_r8(pb));

 }
 

 static int rm_read_extradata(AVIOContext *pb, AVCodecContext *avctx, unsigned size)

 {
     if (size >= 1<<24)
         return -1;
     avctx->extradata = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
     if (!avctx->extradata)

         return AVERROR(ENOMEM);

     avctx->extradata_size = avio_read(pb, avctx->extradata, size);

     memset(avctx->extradata + avctx->extradata_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
     if (avctx->extradata_size != size)
         return AVERROR(EIO);
     return 0;
 }
 

 static void rm_read_metadata(AVFormatContext *s, int wide)
 {
     char buf[1024];
     int i;
     for (i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {

         int len = wide ? avio_rb16(s->pb) : avio_r8(s->pb);

         get_strl(s->pb, buf, sizeof(buf), len);

         av_dict_set(&s->metadata, ff_rm_metadata[i], buf, 0);

     }
 }
 

 RMStream *ff_rm_alloc_rmstream (void)
 {
     RMStream *rms = av_mallocz(sizeof(RMStream));
     rms->curpic_num = -1;
     return rms;
 }
 
 void ff_rm_free_rmstream (RMStream *rms)
 {

     av_free_packet(&rms->pkt);

 }
 

 static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,

                                      AVStream *st, RMStream *ast, int read_all)

 {
     char buf[256];
     uint32_t version;

     int ret;

 
     /* ra type header */

     version = avio_rb16(pb); /* version */

     if (version == 3) {

         int header_size = avio_rb16(pb);

         int64_t startpos = avio_tell(pb);

         avio_skip(pb, 14);

         rm_read_metadata(s, 0);

         if ((startpos + header_size) >= avio_tell(pb) + 2) {

             // fourcc (should always be "lpcJ")

             avio_r8(pb);

             get_str8(pb, buf, sizeof(buf));

         }
         // Skip extra header crap (this should never happen)

         if ((startpos + header_size) > avio_tell(pb))

             avio_skip(pb, header_size + startpos - avio_tell(pb));

         st->codec->sample_rate = 8000;
         st->codec->channels = 1;

         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

         st->codec->codec_id = CODEC_ID_RA_144;

         ast->deint_id = DEINT_ID_INT0;

     } else {
         int flavor, sub_packet_h, coded_framesize, sub_packet_size;

         int codecdata_length;

         /* old version (4) */

         avio_skip(pb, 2); /* unused */

         avio_rb32(pb); /* .ra4 */
         avio_rb32(pb); /* data size */
         avio_rb16(pb); /* version2 */
         avio_rb32(pb); /* header size */
         flavor= avio_rb16(pb); /* add codec info / flavor */
         ast->coded_framesize = coded_framesize = avio_rb32(pb); /* coded frame size */
         avio_rb32(pb); /* ??? */
         avio_rb32(pb); /* ??? */
         avio_rb32(pb); /* ??? */
         ast->sub_packet_h = sub_packet_h = avio_rb16(pb); /* 1 */
         st->codec->block_align= avio_rb16(pb); /* frame size */
         ast->sub_packet_size = sub_packet_size = avio_rb16(pb); /* sub packet size */
         avio_rb16(pb); /* ??? */

         if (version == 5) {

             avio_rb16(pb); avio_rb16(pb); avio_rb16(pb);

         }

         st->codec->sample_rate = avio_rb16(pb);
         avio_rb32(pb);
         st->codec->channels = avio_rb16(pb);

         if (version == 5) {

             ast->deint_id = avio_rl32(pb);

             avio_read(pb, buf, 4);

             buf[4] = 0;
         } else {
             get_str8(pb, buf, sizeof(buf)); /* desc */

             ast->deint_id = AV_RL32(buf);

             get_str8(pb, buf, sizeof(buf)); /* desc */
         }

         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

         st->codec->codec_tag  = AV_RL32(buf);

         st->codec->codec_id   = ff_codec_get_id(ff_rm_codec_tags,
                                                 st->codec->codec_tag);

         switch (st->codec->codec_id) {
         case CODEC_ID_AC3:

             st->need_parsing = AVSTREAM_PARSE_FULL;

             break;
         case CODEC_ID_RA_288:

             st->codec->extradata_size= 0;

             ast->audio_framesize = st->codec->block_align;

             st->codec->block_align = coded_framesize;

             break;
         case CODEC_ID_COOK:
         case CODEC_ID_ATRAC3:
         case CODEC_ID_SIPR:

             avio_rb16(pb); avio_r8(pb);

             if (version == 5)

                 avio_r8(pb);
             codecdata_length = avio_rb32(pb);

             if(codecdata_length + FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)codecdata_length){
                 av_log(s, AV_LOG_ERROR, "codecdata_length too large\n");
                 return -1;
             }
 

             ast->audio_framesize = st->codec->block_align;
             if (st->codec->codec_id == CODEC_ID_SIPR) {
                 if (flavor > 3) {
                     av_log(s, AV_LOG_ERROR, "bad SIPR file flavor %d\n",
                            flavor);
                     return -1;
                 }

                 st->codec->block_align = ff_sipr_subpk_size[flavor];

             } else {
                 if(sub_packet_size <= 0){
                     av_log(s, AV_LOG_ERROR, "sub_packet_size is invalid\n");
                     return -1;
                 }
                 st->codec->block_align = ast->sub_packet_size;
             }

             if ((ret = rm_read_extradata(pb, st->codec, codecdata_length)) < 0)

                 return ret;

             break;
         case CODEC_ID_AAC:

             avio_rb16(pb); avio_r8(pb);

             if (version == 5)

                 avio_r8(pb);
             codecdata_length = avio_rb32(pb);

             if(codecdata_length + FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)codecdata_length){
                 av_log(s, AV_LOG_ERROR, "codecdata_length too large\n");
                 return -1;
             }
             if (codecdata_length >= 1) {

                 avio_r8(pb);

                 if ((ret = rm_read_extradata(pb, st->codec, codecdata_length - 1)) < 0)

                     return ret;

             }

             break;
         default:

             av_strlcpy(st->codec->codec_name, buf, sizeof(st->codec->codec_name));

         }

         if (ast->deint_id == DEINT_ID_INT4 ||
             ast->deint_id == DEINT_ID_GENR ||
             ast->deint_id == DEINT_ID_SIPR) {
             if (st->codec->block_align <= 0 ||
                 ast->audio_framesize * sub_packet_h > (unsigned)INT_MAX ||
                 ast->audio_framesize * sub_packet_h < st->codec->block_align)
                 return AVERROR_INVALIDDATA;
             if (av_new_packet(&ast->pkt, ast->audio_framesize * sub_packet_h) < 0)
                 return AVERROR(ENOMEM);
         }
         switch (ast->deint_id) {
         case DEINT_ID_INT4:
             if (ast->coded_framesize > ast->audio_framesize ||
                 ast->coded_framesize * sub_packet_h > (2 + (sub_packet_h & 1)) * ast->audio_framesize)
                 return AVERROR_INVALIDDATA;
             break;
         case DEINT_ID_GENR:
             if (ast->sub_packet_size <= 0 ||
                 ast->sub_packet_size > ast->audio_framesize)
                 return AVERROR_INVALIDDATA;
             break;
         case DEINT_ID_SIPR:
         case DEINT_ID_INT0:
         case DEINT_ID_VBRS:
         case DEINT_ID_VBRF:
             break;
         default:
             av_log(NULL,0,"Unknown interleaver %X\n", ast->deint_id);
             return AVERROR_INVALIDDATA;
         }
 

         if (read_all) {

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

             rm_read_metadata(s, 0);

         }
     }
     return 0;
 }
 

 int

 ff_rm_read_mdpr_codecdata (AVFormatContext *s, AVIOContext *pb,

                            AVStream *st, RMStream *rst, int codec_data_size)

 {
     unsigned int v;

     int size;

     int64_t codec_pos;

     int ret;

     avpriv_set_pts_info(st, 64, 1, 1000);

     codec_pos = avio_tell(pb);

     v = avio_rb32(pb);

     if (v == MKTAG(0xfd, 'a', 'r', '.')) {
         /* ra type header */

         if (rm_read_audio_stream_info(s, pb, st, rst, 0))

             return -1;
     } else {

         int fps;

         if (avio_rl32(pb) != MKTAG('V', 'I', 'D', 'O')) {

         fail1:

             av_log(s, AV_LOG_WARNING, "Unsupported stream type %08x\n", v);

             goto skip;
         }

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

         st->codec->codec_id  = ff_codec_get_id(ff_rm_codec_tags,
                                                st->codec->codec_tag);

 //        av_log(s, AV_LOG_DEBUG, "%X %X\n", st->codec->codec_tag, MKTAG('R', 'V', '2', '0'));

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

             goto fail1;

         st->codec->width  = avio_rb16(pb);

         st->codec->height = avio_rb16(pb);

         avio_skip(pb, 2); // looks like bits per sample
         avio_skip(pb, 4); // always zero?

         st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

         st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;

         fps = avio_rb32(pb);

         if ((ret = rm_read_extradata(pb, st->codec, codec_data_size - (avio_tell(pb) - codec_pos))) < 0)

             return ret;

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

                   0x10000, fps, (1 << 30) - 1);

         st->avg_frame_rate = st->r_frame_rate;

     }
 
 skip:
     /* skip codec info */

     size = avio_tell(pb) - codec_pos;

     avio_skip(pb, codec_data_size - size);

     return 0;

 }
 

 /** this function assumes that the demuxer has already seeked to the start
  * of the INDX chunk, and will bail out if not. */
 static int rm_read_index(AVFormatContext *s)
 {

     AVIOContext *pb = s->pb;

     unsigned int size, n_pkts, str_id, next_off, n, pos, pts;
     AVStream *st;
 
     do {

         if (avio_rl32(pb) != MKTAG('I','N','D','X'))

             return -1;

         size     = avio_rb32(pb);

         if (size < 20)
             return -1;

         avio_skip(pb, 2);

         n_pkts   = avio_rb32(pb);
         str_id   = avio_rb16(pb);
         next_off = avio_rb32(pb);

         for (n = 0; n < s->nb_streams; n++)
             if (s->streams[n]->id == str_id) {
                 st = s->streams[n];
                 break;
             }
         if (n == s->nb_streams)
             goto skip;
 
         for (n = 0; n < n_pkts; n++) {

             avio_skip(pb, 2);

             pts = avio_rb32(pb);
             pos = avio_rb32(pb);

             avio_skip(pb, 4); /* packet no. */

 
             av_add_index_entry(st, pos, pts, 0, 0, AVINDEX_KEYFRAME);
         }
 
 skip:

         if (next_off && avio_tell(pb) != next_off &&

             avio_seek(pb, next_off, SEEK_SET) < 0)

             return -1;
     } while (next_off);
 
     return 0;
 }

 static int rm_read_header_old(AVFormatContext *s)

 {

     RMDemuxContext *rm = s->priv_data;

     AVStream *st;
 
     rm->old_format = 1;

     st = avformat_new_stream(s, NULL);

     if (!st)
         return -1;

     st->priv_data = ff_rm_alloc_rmstream();
     return rm_read_audio_stream_info(s, s->pb, st, st->priv_data, 1);

 }
 
 static int rm_read_header(AVFormatContext *s, AVFormatParameters *ap)
 {

     RMDemuxContext *rm = s->priv_data;

     AVStream *st;

     AVIOContext *pb = s->pb;

     unsigned int tag;

     int tag_size;

     unsigned int start_time, duration;

     unsigned int data_off = 0, indx_off = 0;

     char buf[128];
     int flags = 0;
 

     tag = avio_rl32(pb);

     if (tag == MKTAG('.', 'r', 'a', 0xfd)) {
         /* very old .ra format */

         return rm_read_header_old(s);

     } else if (tag != MKTAG('.', 'R', 'M', 'F')) {

         return AVERROR(EIO);

     }
 

     avio_rb32(pb); /* header size */
     avio_rb16(pb);
     avio_rb32(pb);
     avio_rb32(pb); /* number of headers */

 
     for(;;) {
         if (url_feof(pb))

             return -1;

         tag = avio_rl32(pb);
         tag_size = avio_rb32(pb);
         avio_rb16(pb);

         av_dlog(s, "tag=%c%c%c%c (%08x) size=%d\n",
                 (tag      ) & 0xff,
                 (tag >>  8) & 0xff,
                 (tag >> 16) & 0xff,
                 (tag >> 24) & 0xff,
                 tag,
                 tag_size);

         if (tag_size < 10 && tag != MKTAG('D', 'A', 'T', 'A'))

             return -1;

         switch(tag) {
         case MKTAG('P', 'R', 'O', 'P'):
             /* file header */

             avio_rb32(pb); /* max bit rate */
             avio_rb32(pb); /* avg bit rate */
             avio_rb32(pb); /* max packet size */
             avio_rb32(pb); /* avg packet size */
             avio_rb32(pb); /* nb packets */
             avio_rb32(pb); /* duration */
             avio_rb32(pb); /* preroll */
             indx_off = avio_rb32(pb); /* index offset */
             data_off = avio_rb32(pb); /* data offset */
             avio_rb16(pb); /* nb streams */
             flags = avio_rb16(pb); /* flags */

             break;
         case MKTAG('C', 'O', 'N', 'T'):

             rm_read_metadata(s, 1);

             break;
         case MKTAG('M', 'D', 'P', 'R'):

             st = avformat_new_stream(s, NULL);

             if (!st)

                 return AVERROR(ENOMEM);

             st->id = avio_rb16(pb);
             avio_rb32(pb); /* max bit rate */
             st->codec->bit_rate = avio_rb32(pb); /* bit rate */
             avio_rb32(pb); /* max packet size */
             avio_rb32(pb); /* avg packet size */
             start_time = avio_rb32(pb); /* start time */
             avio_rb32(pb); /* preroll */
             duration = avio_rb32(pb); /* duration */

             st->start_time = start_time;
             st->duration = duration;
             get_str8(pb, buf, sizeof(buf)); /* desc */
             get_str8(pb, buf, sizeof(buf)); /* mimetype */

             st->codec->codec_type = AVMEDIA_TYPE_DATA;

             st->priv_data = ff_rm_alloc_rmstream();
             if (ff_rm_read_mdpr_codecdata(s, s->pb, st, st->priv_data,

                                           avio_rb32(pb)) < 0)

                 return -1;

             break;
         case MKTAG('D', 'A', 'T', 'A'):
             goto header_end;
         default:
             /* unknown tag: skip it */

             avio_skip(pb, tag_size - 10);

             break;
         }
     }
  header_end:

     rm->nb_packets = avio_rb32(pb); /* number of packets */

     if (!rm->nb_packets && (flags & 4))
         rm->nb_packets = 3600 * 25;

     avio_rb32(pb); /* next data header */

 
     if (!data_off)

         data_off = avio_tell(pb) - 18;

     if (indx_off && pb->seekable && !(s->flags & AVFMT_FLAG_IGNIDX) &&

         avio_seek(pb, indx_off, SEEK_SET) >= 0) {

         rm_read_index(s);

         avio_seek(pb, data_off + 18, SEEK_SET);

     }
 

     return 0;
 }
 

 static int get_num(AVIOContext *pb, int *len)

 {
     int n, n1;
 

     n = avio_rb16(pb);

     (*len)-=2;

     n &= 0x7FFF;

     if (n >= 0x4000) {
         return n - 0x4000;
     } else {

         n1 = avio_rb16(pb);

         (*len)-=2;
         return (n << 16) | n1;
     }
 }
 
 /* multiple of 20 bytes for ra144 (ugly) */
 #define RAW_PACKET_SIZE 1000
 
 static int sync(AVFormatContext *s, int64_t *timestamp, int *flags, int *stream_index, int64_t *pos){

     RMDemuxContext *rm = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *st;
     uint32_t state=0xFFFFFFFF;
 
     while(!url_feof(pb)){

         int len, num, i;

         *pos= avio_tell(pb) - 3;

         if(rm->remaining_len > 0){
             num= rm->current_stream;
             len= rm->remaining_len;
             *timestamp = AV_NOPTS_VALUE;
             *flags= 0;
         }else{

             state= (state<<8) + avio_r8(pb);

 
             if(state == MKBETAG('I', 'N', 'D', 'X')){

                 int n_pkts, expected_len;

                 len = avio_rb32(pb);

                 avio_skip(pb, 2);

                 n_pkts = avio_rb32(pb);

                 expected_len = 20 + n_pkts * 14;
                 if (len == 20)
                     /* some files don't add index entries to chunk size... */
                     len = expected_len;
                 else if (len != expected_len)
                     av_log(s, AV_LOG_WARNING,
                            "Index size %d (%d pkts) is wrong, should be %d.\n",
                            len, n_pkts, expected_len);
                 len -= 14; // we already read part of the index header

                 if(len<0)
                     continue;
                 goto skip;

             } else if (state == MKBETAG('D','A','T','A')) {
                 av_log(s, AV_LOG_WARNING,
                        "DATA tag in middle of chunk, file may be broken.\n");

             }
 

             if(state > (unsigned)0xFFFF || state <= 12)

                 continue;

             len=state - 12;

             state= 0xFFFFFFFF;
 

             num = avio_rb16(pb);
             *timestamp = avio_rb32(pb);
             avio_r8(pb); /* reserved */
             *flags = avio_r8(pb); /* flags */

         }
         for(i=0;i<s->nb_streams;i++) {
             st = s->streams[i];
             if (num == st->id)
                 break;
         }
         if (i == s->nb_streams) {
 skip:
             /* skip packet if unknown number */

             avio_skip(pb, len);

             rm->remaining_len = 0;

             continue;
         }
         *stream_index= i;
 
         return len;
     }
     return -1;
 }
 

 static int rm_assemble_video_frame(AVFormatContext *s, AVIOContext *pb,

                                    RMDemuxContext *rm, RMStream *vst,

                                    AVPacket *pkt, int len, int *pseq,
                                    int64_t *timestamp)

 {
     int hdr, seq, pic_num, len2, pos;
     int type;
 

     hdr = avio_r8(pb); len--;

     type = hdr >> 6;

 
     if(type != 3){  // not frame as a part of packet

         seq = avio_r8(pb); len--;

     }
     if(type != 1){  // not whole frame

         len2 = get_num(pb, &len);

         pos  = get_num(pb, &len);

         pic_num = avio_r8(pb); len--;

     }
     if(len<0)
         return -1;
     rm->remaining_len = len;
     if(type&1){     // frame, not slice

         if(type == 3){  // frame as a part of packet

             len= len2;

             *timestamp = pos;
         }

         if(rm->remaining_len < len)

             return -1;

         rm->remaining_len -= len;

         if(av_new_packet(pkt, len + 9) < 0)
             return AVERROR(EIO);
         pkt->data[0] = 0;
         AV_WL32(pkt->data + 1, 1);
         AV_WL32(pkt->data + 5, 0);

         avio_read(pb, pkt->data + 9, len);

         return 0;
     }
     //now we have to deal with single slice
 

     *pseq = seq;

     if((seq & 0x7F) == 1 || vst->curpic_num != pic_num){
         vst->slices = ((hdr & 0x3F) << 1) + 1;
         vst->videobufsize = len2 + 8*vst->slices + 1;

         av_free_packet(&vst->pkt); //FIXME this should be output.
         if(av_new_packet(&vst->pkt, vst->videobufsize) < 0)

             return AVERROR(ENOMEM);

         vst->videobufpos = 8*vst->slices + 1;
         vst->cur_slice = 0;
         vst->curpic_num = pic_num;

         vst->pktpos = avio_tell(pb);

     }

     if(type == 2)

         len = FFMIN(len, pos);
 

     if(++vst->cur_slice > vst->slices)

         return 1;

     AV_WL32(vst->pkt.data - 7 + 8*vst->cur_slice, 1);
     AV_WL32(vst->pkt.data - 3 + 8*vst->cur_slice, vst->videobufpos - 8*vst->slices - 1);

     if(vst->videobufpos + len > vst->videobufsize)

         return 1;

     if (avio_read(pb, vst->pkt.data + vst->videobufpos, len) != len)

         return AVERROR(EIO);

     vst->videobufpos += len;

     rm->remaining_len-= len;
 

     if(type == 2 || (vst->videobufpos) == vst->videobufsize){

         vst->pkt.data[0] = vst->cur_slice-1;
         *pkt= vst->pkt;

         vst->pkt.data= NULL;

         vst->pkt.size= 0;
         if(vst->slices != vst->cur_slice) //FIXME find out how to set slices correct from the begin

             memmove(pkt->data + 1 + 8*vst->cur_slice, pkt->data + 1 + 8*vst->slices,

                 vst->videobufpos - 1 - 8*vst->slices);

         pkt->size = vst->videobufpos + 8*(vst->cur_slice - vst->slices);

         pkt->pts = AV_NOPTS_VALUE;
         pkt->pos = vst->pktpos;

         vst->slices = 0;

         return 0;

     }
 
     return 1;
 }
 

 static inline void
 rm_ac3_swap_bytes (AVStream *st, AVPacket *pkt)
 {
     uint8_t *ptr;
     int j;
 
     if (st->codec->codec_id == CODEC_ID_AC3) {
         ptr = pkt->data;
         for (j=0;j<pkt->size;j+=2) {
             FFSWAP(int, ptr[0], ptr[1]);
             ptr += 2;
         }
     }
 }
 

 /**
  * Perform 4-bit block reordering for SIPR data.
  * @todo This can be optimized, e.g. use memcpy() if data blocks are aligned
  */

 void ff_rm_reorder_sipr_data(uint8_t *buf, int sub_packet_h, int framesize)

 {

     int n, bs = sub_packet_h * framesize * 2 / 96; // nibbles per subpacket

 
     for (n = 0; n < 38; n++) {
         int j;
         int i = bs * sipr_swaps[n][0];
         int o = bs * sipr_swaps[n][1];
 
         /* swap 4bit-nibbles of block 'i' with 'o' */
         for (j = 0; j < bs; j++, i++, o++) {
             int x = (buf[i >> 1] >> (4 * (i & 1))) & 0xF,
                 y = (buf[o >> 1] >> (4 * (o & 1))) & 0xF;
 
             buf[o >> 1] = (x << (4 * (o & 1))) |
                 (buf[o >> 1] & (0xF << (4 * !(o & 1))));
             buf[i >> 1] = (y << (4 * (i & 1))) |
                 (buf[i >> 1] & (0xF << (4 * !(i & 1))));
         }
     }
 }
 

 int

 ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,

                     AVStream *st, RMStream *ast, int len, AVPacket *pkt,

                     int *seq, int flags, int64_t timestamp)

 {

     RMDemuxContext *rm = s->priv_data;

     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

         rm->current_stream= st->id;

         if(rm_assemble_video_frame(s, pb, rm, ast, pkt, len, seq, &timestamp))

             return -1; //got partial frame

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

         if ((ast->deint_id == DEINT_ID_GENR) ||
             (ast->deint_id == DEINT_ID_INT4) ||
             (ast->deint_id == DEINT_ID_SIPR)) {

             int x;

             int sps = ast->sub_packet_size;
             int cfs = ast->coded_framesize;
             int h = ast->sub_packet_h;
             int y = ast->sub_packet_cnt;
             int w = ast->audio_framesize;

             if (flags & 2)

                 y = ast->sub_packet_cnt = 0;

             if (!y)

                 ast->audiotimestamp = timestamp;

             switch (ast->deint_id) {
                 case DEINT_ID_INT4:

                     for (x = 0; x < h/2; x++)

                         avio_read(pb, ast->pkt.data+x*2*w+y*cfs, cfs);

                     break;

                 case DEINT_ID_GENR:

                     for (x = 0; x < w/sps; x++)

                         avio_read(pb, ast->pkt.data+sps*(h*x+((h+1)/2)*(y&1)+(y>>1)), sps);

                     break;

                 case DEINT_ID_SIPR:

                     avio_read(pb, ast->pkt.data + y * w, w);

                     break;

             }
 

             if (++(ast->sub_packet_cnt) < h)

                 return -1;

             if (ast->deint_id == DEINT_ID_SIPR)

                 ff_rm_reorder_sipr_data(ast->pkt.data, h, w);

              ast->sub_packet_cnt = 0;
              rm->audio_stream_num = st->index;
              rm->audio_pkt_cnt = h * w / st->codec->block_align;

         } else if ((ast->deint_id == DEINT_ID_VBRF) ||
                    (ast->deint_id == DEINT_ID_VBRS)) {

             int x;
             rm->audio_stream_num = st->index;

             ast->sub_packet_cnt = (avio_rb16(pb) & 0xf0) >> 4;

             if (ast->sub_packet_cnt) {
                 for (x = 0; x < ast->sub_packet_cnt; x++)

                     ast->sub_packet_lengths[x] = avio_rb16(pb);

                 rm->audio_pkt_cnt = ast->sub_packet_cnt;

                 ast->audiotimestamp = timestamp;

             } else
                 return -1;

         } else {

             av_get_packet(pb, pkt, len);

             rm_ac3_swap_bytes(st, pkt);

         }

     } else
         av_get_packet(pb, pkt, len);
 
     pkt->stream_index = st->index;
 
 #if 0

     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

         if(st->codec->codec_id == CODEC_ID_RV20){
             int seq= 128*(pkt->data[2]&0x7F) + (pkt->data[3]>>1);

             av_log(s, AV_LOG_DEBUG, "%d %"PRId64" %d\n", *timestamp, *timestamp*512LL/25, seq);

             seq |= (timestamp&~0x3FFF);
             if(seq - timestamp >  0x2000) seq -= 0x4000;
             if(seq - timestamp < -0x2000) seq += 0x4000;

         }
     }
 #endif
 

     pkt->pts = timestamp;

     if (flags & 2)

         pkt->flags |= AV_PKT_FLAG_KEY;

     return st->codec->codec_type == AVMEDIA_TYPE_AUDIO ? rm->audio_pkt_cnt : 0;

 }
 

 int

 ff_rm_retrieve_cache (AVFormatContext *s, AVIOContext *pb,

                       AVStream *st, RMStream *ast, AVPacket *pkt)

 {

     RMDemuxContext *rm = s->priv_data;

 
     assert (rm->audio_pkt_cnt > 0);
 

     if (ast->deint_id == DEINT_ID_VBRF ||
         ast->deint_id == DEINT_ID_VBRS)

         av_get_packet(pb, pkt, ast->sub_packet_lengths[ast->sub_packet_cnt - rm->audio_pkt_cnt]);

     else {
         av_new_packet(pkt, st->codec->block_align);

         memcpy(pkt->data, ast->pkt.data + st->codec->block_align * //FIXME avoid this

                (ast->sub_packet_h * ast->audio_framesize / st->codec->block_align - rm->audio_pkt_cnt),

                st->codec->block_align);
     }
     rm->audio_pkt_cnt--;

     if ((pkt->pts = ast->audiotimestamp) != AV_NOPTS_VALUE) {
         ast->audiotimestamp = AV_NOPTS_VALUE;

         pkt->flags = AV_PKT_FLAG_KEY;

     } else

         pkt->flags = 0;

     pkt->stream_index = st->index;

 
     return rm->audio_pkt_cnt;

 }
 

 static int rm_read_packet(AVFormatContext *s, AVPacket *pkt)
 {

     RMDemuxContext *rm = s->priv_data;

     AVStream *st;

     int i, len, res, seq = 1;

     int64_t timestamp, pos;

     int flags;

     for (;;) {

         if (rm->audio_pkt_cnt) {
             // If there are queued audio packet return them first
             st = s->streams[rm->audio_stream_num];
             ff_rm_retrieve_cache(s, s->pb, st, st->priv_data, pkt);

             flags = 0;

         } else {
             if (rm->old_format) {

                 RMStream *ast;

                 st = s->streams[0];
                 ast = st->priv_data;

                 timestamp = AV_NOPTS_VALUE;
                 len = !ast->audio_framesize ? RAW_PACKET_SIZE :
                     ast->coded_framesize * ast->sub_packet_h / 2;
                 flags = (seq++ == 1) ? 2 : 0;

                 pos = avio_tell(s->pb);

             } else {
                 len=sync(s, &timestamp, &flags, &i, &pos);

                 if (len > 0)
                     st = s->streams[i];

             }
 
             if(len<0 || url_feof(s->pb))
                 return AVERROR(EIO);

             res = ff_rm_parse_packet (s, s->pb, st, st->priv_data, len, pkt,

                                       &seq, flags, timestamp);

             if((flags&2) && (seq&0x7F) == 1)

                 av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME);

             if (res)
                 continue;
         }

         if(  (st->discard >= AVDISCARD_NONKEY && !(flags&2))
            || st->discard >= AVDISCARD_ALL){
             av_free_packet(pkt);

         } else
             break;

     }
 
     return 0;
 }
 
 static int rm_read_close(AVFormatContext *s)
 {

     int i;
 
     for (i=0;i<s->nb_streams;i++)
         ff_rm_free_rmstream(s->streams[i]->priv_data);

 
     return 0;
 }
 
 static int rm_probe(AVProbeData *p)
 {
     /* check file header */
     if ((p->buf[0] == '.' && p->buf[1] == 'R' &&
          p->buf[2] == 'M' && p->buf[3] == 'F' &&
          p->buf[4] == 0 && p->buf[5] == 0) ||
         (p->buf[0] == '.' && p->buf[1] == 'r' &&
          p->buf[2] == 'a' && p->buf[3] == 0xfd))
         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 
 static int64_t rm_read_dts(AVFormatContext *s, int stream_index,
                                int64_t *ppos, int64_t pos_limit)
 {

     RMDemuxContext *rm = s->priv_data;

     int64_t pos, dts;
     int stream_index2, flags, len, h;
 
     pos = *ppos;
 
     if(rm->old_format)
         return AV_NOPTS_VALUE;
 

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

     rm->remaining_len=0;
     for(;;){
         int seq=1;
         AVStream *st;
 
         len=sync(s, &dts, &flags, &stream_index2, &pos);
         if(len<0)
             return AV_NOPTS_VALUE;
 
         st = s->streams[stream_index2];

         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {

             h= avio_r8(s->pb); len--;

             if(!(h & 0x40)){

                 seq = avio_r8(s->pb); len--;

             }
         }
 
         if((flags&2) && (seq&0x7F) == 1){
 //            av_log(s, AV_LOG_DEBUG, "%d %d-%d %"PRId64" %d\n", flags, stream_index2, stream_index, dts, seq);
             av_add_index_entry(st, pos, dts, 0, 0, AVINDEX_KEYFRAME);
             if(stream_index2 == stream_index)
                 break;
         }
 

         avio_skip(s->pb, len);

     }
     *ppos = pos;
     return dts;
 }
 

 AVInputFormat ff_rm_demuxer = {

     .name           = "rm",
     .long_name      = NULL_IF_CONFIG_SMALL("RealMedia format"),
     .priv_data_size = sizeof(RMDemuxContext),
     .read_probe     = rm_probe,
     .read_header    = rm_read_header,
     .read_packet    = rm_read_packet,
     .read_close     = rm_read_close,
     .read_timestamp = rm_read_dts,

 };

 AVInputFormat ff_rdt_demuxer = {

     .name           = "rdt",
     .long_name      = NULL_IF_CONFIG_SMALL("RDT demuxer"),
     .priv_data_size = sizeof(RMDemuxContext),
     .read_close     = rm_read_close,

     .flags          = AVFMT_NOFILE,

 };