/*

  * Flash Compatible Streaming Format demuxer

  * Copyright (c) 2000 Fabrice Bellard
  * Copyright (c) 2003 Tinic Uro

  *
  * 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/intreadwrite.h"

 #include "swf.h"
 

 static int get_swf_tag(AVIOContext *pb, int *len_ptr)

 {
     int tag, len;
 
     if (url_feof(pb))
         return -1;
 

     tag = avio_rl16(pb);

     len = tag & 0x3f;
     tag = tag >> 6;
     if (len == 0x3f) {

         len = avio_rl32(pb);

     }
 //    av_log(NULL, AV_LOG_DEBUG, "Tag: %d - Len: %d\n", tag, len);
     *len_ptr = len;
     return tag;
 }
 
 
 static int swf_probe(AVProbeData *p)
 {
     /* check file header */
     if ((p->buf[0] == 'F' || p->buf[0] == 'C') && p->buf[1] == 'W' &&
         p->buf[2] == 'S')
         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 
 static int swf_read_header(AVFormatContext *s, AVFormatParameters *ap)
 {
     SWFContext *swf = s->priv_data;

     AVIOContext *pb = s->pb;

     int nbits, len, tag;
 

     tag = avio_rb32(pb) & 0xffffff00;

 
     if (tag == MKBETAG('C', 'W', 'S', 0)) {
         av_log(s, AV_LOG_ERROR, "Compressed SWF format not supported\n");
         return AVERROR(EIO);
     }
     if (tag != MKBETAG('F', 'W', 'S', 0))
         return AVERROR(EIO);

     avio_rl32(pb);

     /* skip rectangle size */

     nbits = avio_r8(pb) >> 3;

     len = (4 * nbits - 3 + 7) / 8;

     avio_skip(pb, len);

     swf->frame_rate = avio_rl16(pb); /* 8.8 fixed */
     avio_rl16(pb); /* frame count */

 
     swf->samples_per_frame = 0;
     s->ctx_flags |= AVFMTCTX_NOHEADER;
     return 0;
 }
 
 static int swf_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     SWFContext *swf = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *vst = NULL, *ast = NULL, *st = 0;
     int tag, len, i, frame, v;
 
     for(;;) {

         uint64_t pos = avio_tell(pb);

         tag = get_swf_tag(pb, &len);
         if (tag < 0)
             return AVERROR(EIO);

         if (tag == TAG_VIDEOSTREAM) {

             int ch_id = avio_rl16(pb);

             len -= 2;
 
             for (i=0; i<s->nb_streams; i++) {
                 st = s->streams[i];

                 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id)

                     goto skip;
             }
 

             avio_rl16(pb);
             avio_rl16(pb);
             avio_rl16(pb);
             avio_r8(pb);

             /* Check for FLV1 */
             vst = av_new_stream(s, ch_id);
             if (!vst)
                 return -1;

             vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

             vst->codec->codec_id = ff_codec_get_id(swf_codec_tags, avio_r8(pb));

             av_set_pts_info(vst, 16, 256, swf->frame_rate);

             vst->codec->time_base = (AVRational){ 256, swf->frame_rate };

             len -= 8;
         } else if (tag == TAG_STREAMHEAD || tag == TAG_STREAMHEAD2) {

             /* streaming found */
             int sample_rate_code;

 
             for (i=0; i<s->nb_streams; i++) {
                 st = s->streams[i];

                 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1)

                     goto skip;
             }
 

             avio_r8(pb);
             v = avio_r8(pb);
             swf->samples_per_frame = avio_rl16(pb);

             ast = av_new_stream(s, -1); /* -1 to avoid clash with video stream ch_id */
             if (!ast)
                 return -1;
             ast->codec->channels = 1 + (v&1);

             ast->codec->codec_type = AVMEDIA_TYPE_AUDIO;

             ast->codec->codec_id = ff_codec_get_id(swf_audio_codec_tags, (v>>4) & 15);

             ast->need_parsing = AVSTREAM_PARSE_FULL;
             sample_rate_code= (v>>2) & 3;
             if (!sample_rate_code)
                 return AVERROR(EIO);
             ast->codec->sample_rate = 11025 << (sample_rate_code-1);
             av_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
             len -= 4;
         } else if (tag == TAG_VIDEOFRAME) {

             int ch_id = avio_rl16(pb);

             len -= 2;
             for(i=0; i<s->nb_streams; i++) {
                 st = s->streams[i];

                 if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && st->id == ch_id) {

                     frame = avio_rl16(pb);

                     av_get_packet(pb, pkt, len-2);

                     pkt->pos = pos;

                     pkt->pts = frame;
                     pkt->stream_index = st->index;
                     return pkt->size;
                 }
             }
         } else if (tag == TAG_STREAMBLOCK) {

             for (i = 0; i < s->nb_streams; i++) {
                 st = s->streams[i];

                 if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && st->id == -1) {

             if (st->codec->codec_id == CODEC_ID_MP3) {

                 avio_skip(pb, 4);

                 av_get_packet(pb, pkt, len-4);
             } else { // ADPCM, PCM
                 av_get_packet(pb, pkt, len);
             }

             pkt->pos = pos;

             pkt->stream_index = st->index;
             return pkt->size;

                 }
             }

         } else if (tag == TAG_JPEG2) {
             for (i=0; i<s->nb_streams; i++) {
                 st = s->streams[i];

                 if (st->codec->codec_id == CODEC_ID_MJPEG && st->id == -2)

                     break;
             }
             if (i == s->nb_streams) {
                 vst = av_new_stream(s, -2); /* -2 to avoid clash with video stream and audio stream */
                 if (!vst)
                     return -1;

                 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

                 vst->codec->codec_id = CODEC_ID_MJPEG;
                 av_set_pts_info(vst, 64, 256, swf->frame_rate);
                 vst->codec->time_base = (AVRational){ 256, swf->frame_rate };
                 st = vst;
             }

             avio_rl16(pb); /* BITMAP_ID */

             av_new_packet(pkt, len-2);

             avio_read(pb, pkt->data, 4);

             if (AV_RB32(pkt->data) == 0xffd8ffd9 ||
                 AV_RB32(pkt->data) == 0xffd9ffd8) {
                 /* old SWF files containing SOI/EOI as data start */
                 /* files created by swink have reversed tag */
                 pkt->size -= 4;

                 avio_read(pb, pkt->data, pkt->size);

             } else {

                 avio_read(pb, pkt->data + 4, pkt->size - 4);

             }

             pkt->pos = pos;

             pkt->stream_index = st->index;
             return pkt->size;
         }

     skip:

         avio_skip(pb, len);

     }
     return 0;
 }
 

 AVInputFormat ff_swf_demuxer = {

     "swf",

     NULL_IF_CONFIG_SMALL("Flash format"),

     sizeof(SWFContext),
     swf_probe,
     swf_read_header,
     swf_read_packet,
 };