/*
  * Tiertex Limited SEQ File Demuxer
  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
  *
  * 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
  */
 
 /**

  * @file

  * Tiertex Limited SEQ file demuxer
  */
 
 #include "avformat.h"

 #include "internal.h"

 
 #define SEQ_FRAME_SIZE         6144
 #define SEQ_FRAME_W            256
 #define SEQ_FRAME_H            128
 #define SEQ_NUM_FRAME_BUFFERS  30
 #define SEQ_AUDIO_BUFFER_SIZE  882
 #define SEQ_SAMPLE_RATE        22050
 #define SEQ_FRAME_RATE         25
 
 
 typedef struct TiertexSeqFrameBuffer {
     int fill_size;
     int data_size;
     unsigned char *data;
 } TiertexSeqFrameBuffer;
 
 typedef struct SeqDemuxContext {
     int audio_stream_index;
     int video_stream_index;
     int current_frame_pts;
     int current_frame_offs;
     TiertexSeqFrameBuffer frame_buffers[SEQ_NUM_FRAME_BUFFERS];
     int frame_buffers_count;
     unsigned int current_audio_data_size;
     unsigned int current_audio_data_offs;
     unsigned int current_pal_data_size;
     unsigned int current_pal_data_offs;
     unsigned int current_video_data_size;
     unsigned char *current_video_data_ptr;
     int audio_buffer_full;
 } SeqDemuxContext;
 
 
 static int seq_probe(AVProbeData *p)
 {
     int i;
 

     if (p->buf_size < 258)

         return 0;
 
     /* there's no real header in a .seq file, the only thing they have in common */
     /* is the first 256 bytes of the file which are always filled with 0 */
     for (i = 0; i < 256; i++)

         if (p->buf[i])

             return 0;
 

     if(p->buf[256]==0 && p->buf[257]==0)
         return 0;
 

     /* only one fourth of the score since the previous check is too naive */
     return AVPROBE_SCORE_MAX / 4;
 }
 

 static int seq_init_frame_buffers(SeqDemuxContext *seq, AVIOContext *pb)

 {
     int i, sz;
     TiertexSeqFrameBuffer *seq_buffer;
 

     avio_seek(pb, 256, SEEK_SET);

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

         sz = avio_rl16(pb);

         if (sz == 0)
             break;
         else {
             seq_buffer = &seq->frame_buffers[i];
             seq_buffer->fill_size = 0;
             seq_buffer->data_size = sz;
             seq_buffer->data = av_malloc(sz);
             if (!seq_buffer->data)

                 return AVERROR(ENOMEM);

         }
     }
     seq->frame_buffers_count = i;
     return 0;
 }
 

 static int seq_fill_buffer(SeqDemuxContext *seq, AVIOContext *pb, int buffer_num, unsigned int data_offs, int data_size)

 {
     TiertexSeqFrameBuffer *seq_buffer;
 
     if (buffer_num >= SEQ_NUM_FRAME_BUFFERS)
         return AVERROR_INVALIDDATA;
 
     seq_buffer = &seq->frame_buffers[buffer_num];

     if (seq_buffer->fill_size + data_size > seq_buffer->data_size || data_size <= 0)

         return AVERROR_INVALIDDATA;
 

     avio_seek(pb, seq->current_frame_offs + data_offs, SEEK_SET);

     if (avio_read(pb, seq_buffer->data + seq_buffer->fill_size, data_size) != data_size)

         return AVERROR(EIO);

 
     seq_buffer->fill_size += data_size;
     return 0;
 }
 

 static int seq_parse_frame_data(SeqDemuxContext *seq, AVIOContext *pb)

 {
     unsigned int offset_table[4], buffer_num[4];
     TiertexSeqFrameBuffer *seq_buffer;

     int i, e, err;

 
     seq->current_frame_offs += SEQ_FRAME_SIZE;

     avio_seek(pb, seq->current_frame_offs, SEEK_SET);

 
     /* sound data */

     seq->current_audio_data_offs = avio_rl16(pb);

     if (seq->current_audio_data_offs) {

         seq->current_audio_data_size = SEQ_AUDIO_BUFFER_SIZE * 2;
     } else {
         seq->current_audio_data_size = 0;
     }
 
     /* palette data */

     seq->current_pal_data_offs = avio_rl16(pb);

     if (seq->current_pal_data_offs) {

         seq->current_pal_data_size = 768;
     } else {
         seq->current_pal_data_size = 0;
     }
 
     /* video data */
     for (i = 0; i < 4; i++)

         buffer_num[i] = avio_r8(pb);

 
     for (i = 0; i < 4; i++)

         offset_table[i] = avio_rl16(pb);

 
     for (i = 0; i < 3; i++) {

         if (offset_table[i]) {

             for (e = i + 1; e < 3 && offset_table[e] == 0; e++);

             err = seq_fill_buffer(seq, pb, buffer_num[1 + i],

               offset_table[i],
               offset_table[e] - offset_table[i]);

             if (err)

                 return err;

         }
     }
 
     if (buffer_num[0] != 255) {

         if (buffer_num[0] >= SEQ_NUM_FRAME_BUFFERS)
             return AVERROR_INVALIDDATA;
 

         seq_buffer = &seq->frame_buffers[buffer_num[0]];
         seq->current_video_data_size = seq_buffer->fill_size;
         seq->current_video_data_ptr  = seq_buffer->data;
         seq_buffer->fill_size = 0;
     } else {
         seq->current_video_data_size = 0;
         seq->current_video_data_ptr  = 0;
     }
 
     return 0;
 }
 

 static int seq_read_header(AVFormatContext *s)

 {
     int i, rc;

     SeqDemuxContext *seq = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *st;
 
     /* init internal buffers */
     rc = seq_init_frame_buffers(seq, pb);
     if (rc)
         return rc;
 
     seq->current_frame_offs = 0;
 
     /* preload (no audio data, just buffer operations related data) */
     for (i = 1; i <= 100; i++) {
         rc = seq_parse_frame_data(seq, pb);
         if (rc)
             return rc;
     }
 
     seq->current_frame_pts = 0;
 
     seq->audio_buffer_full = 0;
 
     /* initialize the video decoder stream */

     st = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

     avpriv_set_pts_info(st, 32, 1, SEQ_FRAME_RATE);

     seq->video_stream_index = st->index;

     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

     st->codec->codec_id = CODEC_ID_TIERTEXSEQVIDEO;
     st->codec->codec_tag = 0;  /* no fourcc */
     st->codec->width = SEQ_FRAME_W;
     st->codec->height = SEQ_FRAME_H;
 
     /* initialize the audio decoder stream */

     st = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

     st->start_time = 0;

     avpriv_set_pts_info(st, 32, 1, SEQ_SAMPLE_RATE);

     seq->audio_stream_index = st->index;

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->codec_id = CODEC_ID_PCM_S16BE;
     st->codec->codec_tag = 0;  /* no tag */
     st->codec->channels = 1;
     st->codec->sample_rate = SEQ_SAMPLE_RATE;

     st->codec->bits_per_coded_sample = 16;
     st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_coded_sample * st->codec->channels;

     st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample / 8;

 
     return 0;
 }
 
 static int seq_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     int rc;

     SeqDemuxContext *seq = s->priv_data;

     AVIOContext *pb = s->pb;

 
     if (!seq->audio_buffer_full) {
         rc = seq_parse_frame_data(seq, pb);
         if (rc)
             return rc;
 
         /* video packet */
         if (seq->current_pal_data_size + seq->current_video_data_size != 0) {
             if (av_new_packet(pkt, 1 + seq->current_pal_data_size + seq->current_video_data_size))

                 return AVERROR(ENOMEM);

 
             pkt->data[0] = 0;

             if (seq->current_pal_data_size) {

                 pkt->data[0] |= 1;

                 avio_seek(pb, seq->current_frame_offs + seq->current_pal_data_offs, SEEK_SET);

                 if (avio_read(pb, &pkt->data[1], seq->current_pal_data_size) != seq->current_pal_data_size)

                     return AVERROR(EIO);

             }

             if (seq->current_video_data_size) {

                 pkt->data[0] |= 2;
                 memcpy(&pkt->data[1 + seq->current_pal_data_size],
                   seq->current_video_data_ptr,
                   seq->current_video_data_size);
             }
             pkt->stream_index = seq->video_stream_index;
             pkt->pts = seq->current_frame_pts;
 
             /* sound buffer will be processed on next read_packet() call */
             seq->audio_buffer_full = 1;
             return 0;
        }
     }
 
     /* audio packet */
     if (seq->current_audio_data_offs == 0) /* end of data reached */

         return AVERROR(EIO);

     avio_seek(pb, seq->current_frame_offs + seq->current_audio_data_offs, SEEK_SET);

     rc = av_get_packet(pb, pkt, seq->current_audio_data_size);
     if (rc < 0)
         return rc;
 
     pkt->stream_index = seq->audio_stream_index;

     seq->current_frame_pts++;

 
     seq->audio_buffer_full = 0;
     return 0;
 }
 
 static int seq_read_close(AVFormatContext *s)
 {
     int i;

     SeqDemuxContext *seq = s->priv_data;

 
     for (i = 0; i < SEQ_NUM_FRAME_BUFFERS; i++)
         av_free(seq->frame_buffers[i].data);
 
     return 0;
 }
 

 AVInputFormat ff_tiertexseq_demuxer = {

     .name           = "tiertexseq",
     .long_name      = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ format"),
     .priv_data_size = sizeof(SeqDemuxContext),
     .read_probe     = seq_probe,
     .read_header    = seq_read_header,
     .read_packet    = seq_read_packet,
     .read_close     = seq_read_close,

 };