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libavformat/tiertexseq.c

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00001 /*
00002  * Tiertex Limited SEQ File Demuxer
00003  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "avformat.h"
00028 #include "internal.h"
00029 
00030 #define SEQ_FRAME_SIZE         6144
00031 #define SEQ_FRAME_W            256
00032 #define SEQ_FRAME_H            128
00033 #define SEQ_NUM_FRAME_BUFFERS  30
00034 #define SEQ_AUDIO_BUFFER_SIZE  882
00035 #define SEQ_SAMPLE_RATE        22050
00036 #define SEQ_FRAME_RATE         25
00037 
00038 
00039 typedef struct TiertexSeqFrameBuffer {
00040     int fill_size;
00041     int data_size;
00042     unsigned char *data;
00043 } TiertexSeqFrameBuffer;
00044 
00045 typedef struct SeqDemuxContext {
00046     int audio_stream_index;
00047     int video_stream_index;
00048     int current_frame_pts;
00049     int current_frame_offs;
00050     TiertexSeqFrameBuffer frame_buffers[SEQ_NUM_FRAME_BUFFERS];
00051     int frame_buffers_count;
00052     unsigned int current_audio_data_size;
00053     unsigned int current_audio_data_offs;
00054     unsigned int current_pal_data_size;
00055     unsigned int current_pal_data_offs;
00056     unsigned int current_video_data_size;
00057     unsigned char *current_video_data_ptr;
00058     int audio_buffer_full;
00059 } SeqDemuxContext;
00060 
00061 
00062 static int seq_probe(AVProbeData *p)
00063 {
00064     int i;
00065 
00066     if (p->buf_size < 258)
00067         return 0;
00068 
00069     /* there's no real header in a .seq file, the only thing they have in common */
00070     /* is the first 256 bytes of the file which are always filled with 0 */
00071     for (i = 0; i < 256; i++)
00072         if (p->buf[i])
00073             return 0;
00074 
00075     if(p->buf[256]==0 && p->buf[257]==0)
00076         return 0;
00077 
00078     /* only one fourth of the score since the previous check is too naive */
00079     return AVPROBE_SCORE_MAX / 4;
00080 }
00081 
00082 static int seq_init_frame_buffers(SeqDemuxContext *seq, AVIOContext *pb)
00083 {
00084     int i, sz;
00085     TiertexSeqFrameBuffer *seq_buffer;
00086 
00087     avio_seek(pb, 256, SEEK_SET);
00088 
00089     for (i = 0; i < SEQ_NUM_FRAME_BUFFERS; i++) {
00090         sz = avio_rl16(pb);
00091         if (sz == 0)
00092             break;
00093         else {
00094             seq_buffer = &seq->frame_buffers[i];
00095             seq_buffer->fill_size = 0;
00096             seq_buffer->data_size = sz;
00097             seq_buffer->data = av_malloc(sz);
00098             if (!seq_buffer->data)
00099                 return AVERROR(ENOMEM);
00100         }
00101     }
00102     seq->frame_buffers_count = i;
00103     return 0;
00104 }
00105 
00106 static int seq_fill_buffer(SeqDemuxContext *seq, AVIOContext *pb, int buffer_num, unsigned int data_offs, int data_size)
00107 {
00108     TiertexSeqFrameBuffer *seq_buffer;
00109 
00110     if (buffer_num >= SEQ_NUM_FRAME_BUFFERS)
00111         return AVERROR_INVALIDDATA;
00112 
00113     seq_buffer = &seq->frame_buffers[buffer_num];
00114     if (seq_buffer->fill_size + data_size > seq_buffer->data_size || data_size <= 0)
00115         return AVERROR_INVALIDDATA;
00116 
00117     avio_seek(pb, seq->current_frame_offs + data_offs, SEEK_SET);
00118     if (avio_read(pb, seq_buffer->data + seq_buffer->fill_size, data_size) != data_size)
00119         return AVERROR(EIO);
00120 
00121     seq_buffer->fill_size += data_size;
00122     return 0;
00123 }
00124 
00125 static int seq_parse_frame_data(SeqDemuxContext *seq, AVIOContext *pb)
00126 {
00127     unsigned int offset_table[4], buffer_num[4];
00128     TiertexSeqFrameBuffer *seq_buffer;
00129     int i, e, err;
00130 
00131     seq->current_frame_offs += SEQ_FRAME_SIZE;
00132     avio_seek(pb, seq->current_frame_offs, SEEK_SET);
00133 
00134     /* sound data */
00135     seq->current_audio_data_offs = avio_rl16(pb);
00136     if (seq->current_audio_data_offs) {
00137         seq->current_audio_data_size = SEQ_AUDIO_BUFFER_SIZE * 2;
00138     } else {
00139         seq->current_audio_data_size = 0;
00140     }
00141 
00142     /* palette data */
00143     seq->current_pal_data_offs = avio_rl16(pb);
00144     if (seq->current_pal_data_offs) {
00145         seq->current_pal_data_size = 768;
00146     } else {
00147         seq->current_pal_data_size = 0;
00148     }
00149 
00150     /* video data */
00151     for (i = 0; i < 4; i++)
00152         buffer_num[i] = avio_r8(pb);
00153 
00154     for (i = 0; i < 4; i++)
00155         offset_table[i] = avio_rl16(pb);
00156 
00157     for (i = 0; i < 3; i++) {
00158         if (offset_table[i]) {
00159             for (e = i + 1; e < 3 && offset_table[e] == 0; e++);
00160             err = seq_fill_buffer(seq, pb, buffer_num[1 + i],
00161               offset_table[i],
00162               offset_table[e] - offset_table[i]);
00163             if (err)
00164                 return err;
00165         }
00166     }
00167 
00168     if (buffer_num[0] != 255) {
00169         if (buffer_num[0] >= SEQ_NUM_FRAME_BUFFERS)
00170             return AVERROR_INVALIDDATA;
00171 
00172         seq_buffer = &seq->frame_buffers[buffer_num[0]];
00173         seq->current_video_data_size = seq_buffer->fill_size;
00174         seq->current_video_data_ptr  = seq_buffer->data;
00175         seq_buffer->fill_size = 0;
00176     } else {
00177         seq->current_video_data_size = 0;
00178         seq->current_video_data_ptr  = 0;
00179     }
00180 
00181     return 0;
00182 }
00183 
00184 static int seq_read_header(AVFormatContext *s, AVFormatParameters *ap)
00185 {
00186     int i, rc;
00187     SeqDemuxContext *seq = s->priv_data;
00188     AVIOContext *pb = s->pb;
00189     AVStream *st;
00190 
00191     /* init internal buffers */
00192     rc = seq_init_frame_buffers(seq, pb);
00193     if (rc)
00194         return rc;
00195 
00196     seq->current_frame_offs = 0;
00197 
00198     /* preload (no audio data, just buffer operations related data) */
00199     for (i = 1; i <= 100; i++) {
00200         rc = seq_parse_frame_data(seq, pb);
00201         if (rc)
00202             return rc;
00203     }
00204 
00205     seq->current_frame_pts = 0;
00206 
00207     seq->audio_buffer_full = 0;
00208 
00209     /* initialize the video decoder stream */
00210     st = avformat_new_stream(s, NULL);
00211     if (!st)
00212         return AVERROR(ENOMEM);
00213 
00214     avpriv_set_pts_info(st, 32, 1, SEQ_FRAME_RATE);
00215     seq->video_stream_index = st->index;
00216     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00217     st->codec->codec_id = CODEC_ID_TIERTEXSEQVIDEO;
00218     st->codec->codec_tag = 0;  /* no fourcc */
00219     st->codec->width = SEQ_FRAME_W;
00220     st->codec->height = SEQ_FRAME_H;
00221 
00222     /* initialize the audio decoder stream */
00223     st = avformat_new_stream(s, NULL);
00224     if (!st)
00225         return AVERROR(ENOMEM);
00226 
00227     avpriv_set_pts_info(st, 32, 1, SEQ_SAMPLE_RATE);
00228     seq->audio_stream_index = st->index;
00229     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00230     st->codec->codec_id = CODEC_ID_PCM_S16BE;
00231     st->codec->codec_tag = 0;  /* no tag */
00232     st->codec->channels = 1;
00233     st->codec->sample_rate = SEQ_SAMPLE_RATE;
00234     st->codec->bits_per_coded_sample = 16;
00235     st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_coded_sample * st->codec->channels;
00236     st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
00237 
00238     return 0;
00239 }
00240 
00241 static int seq_read_packet(AVFormatContext *s, AVPacket *pkt)
00242 {
00243     int rc;
00244     SeqDemuxContext *seq = s->priv_data;
00245     AVIOContext *pb = s->pb;
00246 
00247     if (!seq->audio_buffer_full) {
00248         rc = seq_parse_frame_data(seq, pb);
00249         if (rc)
00250             return rc;
00251 
00252         /* video packet */
00253         if (seq->current_pal_data_size + seq->current_video_data_size != 0) {
00254             if (av_new_packet(pkt, 1 + seq->current_pal_data_size + seq->current_video_data_size))
00255                 return AVERROR(ENOMEM);
00256 
00257             pkt->data[0] = 0;
00258             if (seq->current_pal_data_size) {
00259                 pkt->data[0] |= 1;
00260                 avio_seek(pb, seq->current_frame_offs + seq->current_pal_data_offs, SEEK_SET);
00261                 if (avio_read(pb, &pkt->data[1], seq->current_pal_data_size) != seq->current_pal_data_size)
00262                     return AVERROR(EIO);
00263             }
00264             if (seq->current_video_data_size) {
00265                 pkt->data[0] |= 2;
00266                 memcpy(&pkt->data[1 + seq->current_pal_data_size],
00267                   seq->current_video_data_ptr,
00268                   seq->current_video_data_size);
00269             }
00270             pkt->stream_index = seq->video_stream_index;
00271             pkt->pts = seq->current_frame_pts;
00272 
00273             /* sound buffer will be processed on next read_packet() call */
00274             seq->audio_buffer_full = 1;
00275             return 0;
00276        }
00277     }
00278 
00279     /* audio packet */
00280     if (seq->current_audio_data_offs == 0) /* end of data reached */
00281         return AVERROR(EIO);
00282 
00283     avio_seek(pb, seq->current_frame_offs + seq->current_audio_data_offs, SEEK_SET);
00284     rc = av_get_packet(pb, pkt, seq->current_audio_data_size);
00285     if (rc < 0)
00286         return rc;
00287 
00288     pkt->stream_index = seq->audio_stream_index;
00289     seq->current_frame_pts++;
00290 
00291     seq->audio_buffer_full = 0;
00292     return 0;
00293 }
00294 
00295 static int seq_read_close(AVFormatContext *s)
00296 {
00297     int i;
00298     SeqDemuxContext *seq = s->priv_data;
00299 
00300     for (i = 0; i < SEQ_NUM_FRAME_BUFFERS; i++)
00301         av_free(seq->frame_buffers[i].data);
00302 
00303     return 0;
00304 }
00305 
00306 AVInputFormat ff_tiertexseq_demuxer = {
00307     .name           = "tiertexseq",
00308     .long_name      = NULL_IF_CONFIG_SMALL("Tiertex Limited SEQ format"),
00309     .priv_data_size = sizeof(SeqDemuxContext),
00310     .read_probe     = seq_probe,
00311     .read_header    = seq_read_header,
00312     .read_packet    = seq_read_packet,
00313     .read_close     = seq_read_close,
00314 };
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