yading@11: /*
yading@11:  * RL2 Format Demuxer
yading@11:  * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * RL2 file demuxer
yading@11:  * @file
yading@11:  * @author Sascha Sommer (saschasommer@freenet.de)
yading@11:  * @see http://wiki.multimedia.cx/index.php?title=RL2
yading@11:  *
yading@11:  * extradata:
yading@11:  * 2 byte le initial drawing offset within 320x200 viewport
yading@11:  * 4 byte le number of used colors
yading@11:  * 256 * 3 bytes rgb palette
yading@11:  * optional background_frame
yading@11:  */
yading@11: 
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "libavutil/mathematics.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: 
yading@11: #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
yading@11: 
yading@11: #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
yading@11: #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
yading@11: #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
yading@11: 
yading@11: typedef struct Rl2DemuxContext {
yading@11:     unsigned int index_pos[2];   ///< indexes in the sample tables
yading@11: } Rl2DemuxContext;
yading@11: 
yading@11: 
yading@11: /**
yading@11:  * check if the file is in rl2 format
yading@11:  * @param p probe buffer
yading@11:  * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
yading@11:  */
yading@11: static int rl2_probe(AVProbeData *p)
yading@11: {
yading@11: 
yading@11:     if(AV_RB32(&p->buf[0]) != FORM_TAG)
yading@11:         return 0;
yading@11: 
yading@11:     if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
yading@11:         AV_RB32(&p->buf[8]) != RLV3_TAG)
yading@11:         return 0;
yading@11: 
yading@11:     return AVPROBE_SCORE_MAX;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * read rl2 header data and setup the avstreams
yading@11:  * @param s demuxer context
yading@11:  * @return 0 on success, AVERROR otherwise
yading@11:  */
yading@11: static av_cold int rl2_read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVStream *st;
yading@11:     unsigned int frame_count;
yading@11:     unsigned int audio_frame_counter = 0;
yading@11:     unsigned int video_frame_counter = 0;
yading@11:     unsigned int back_size;
yading@11:     unsigned short sound_rate;
yading@11:     unsigned short rate;
yading@11:     unsigned short channels;
yading@11:     unsigned short def_sound_size;
yading@11:     unsigned int signature;
yading@11:     unsigned int pts_den = 11025; /* video only case */
yading@11:     unsigned int pts_num = 1103;
yading@11:     unsigned int* chunk_offset = NULL;
yading@11:     int* chunk_size = NULL;
yading@11:     int* audio_size = NULL;
yading@11:     int i;
yading@11:     int ret = 0;
yading@11: 
yading@11:     avio_skip(pb,4);          /* skip FORM tag */
yading@11:     back_size = avio_rl32(pb); /**< get size of the background frame */
yading@11:     signature = avio_rb32(pb);
yading@11:     avio_skip(pb, 4);         /* data size */
yading@11:     frame_count = avio_rl32(pb);
yading@11: 
yading@11:     /* disallow back_sizes and frame_counts that may lead to overflows later */
yading@11:     if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
yading@11:         return AVERROR_INVALIDDATA;
yading@11: 
yading@11:     avio_skip(pb, 2);         /* encoding mentod */
yading@11:     sound_rate = avio_rl16(pb);
yading@11:     rate = avio_rl16(pb);
yading@11:     channels = avio_rl16(pb);
yading@11:     def_sound_size = avio_rl16(pb);
yading@11: 
yading@11:     /** setup video stream */
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if(!st)
yading@11:          return AVERROR(ENOMEM);
yading@11: 
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
yading@11:     st->codec->codec_id = AV_CODEC_ID_RL2;
yading@11:     st->codec->codec_tag = 0;  /* no fourcc */
yading@11:     st->codec->width = 320;
yading@11:     st->codec->height = 200;
yading@11: 
yading@11:     /** allocate and fill extradata */
yading@11:     st->codec->extradata_size = EXTRADATA1_SIZE;
yading@11: 
yading@11:     if(signature == RLV3_TAG && back_size > 0)
yading@11:         st->codec->extradata_size += back_size;
yading@11: 
yading@11:     st->codec->extradata = av_mallocz(st->codec->extradata_size +
yading@11:                                           FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:     if(!st->codec->extradata)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
yading@11:                       st->codec->extradata_size)
yading@11:         return AVERROR(EIO);
yading@11: 
yading@11:     /** setup audio stream if present */
yading@11:     if(sound_rate){
yading@11:         if(channels <= 0)
yading@11:             return AVERROR_INVALIDDATA;
yading@11: 
yading@11:         pts_num = def_sound_size;
yading@11:         pts_den = rate;
yading@11: 
yading@11:         st = avformat_new_stream(s, NULL);
yading@11:         if (!st)
yading@11:             return AVERROR(ENOMEM);
yading@11:         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:         st->codec->codec_id = AV_CODEC_ID_PCM_U8;
yading@11:         st->codec->codec_tag = 1;
yading@11:         st->codec->channels = channels;
yading@11:         st->codec->bits_per_coded_sample = 8;
yading@11:         st->codec->sample_rate = rate;
yading@11:         st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
yading@11:             st->codec->bits_per_coded_sample;
yading@11:         st->codec->block_align = st->codec->channels *
yading@11:             st->codec->bits_per_coded_sample / 8;
yading@11:         avpriv_set_pts_info(st,32,1,rate);
yading@11:     }
yading@11: 
yading@11:     avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
yading@11: 
yading@11:     chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
yading@11:     audio_size =   av_malloc(frame_count * sizeof(uint32_t));
yading@11:     chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
yading@11: 
yading@11:     if(!chunk_size || !audio_size || !chunk_offset){
yading@11:         av_free(chunk_size);
yading@11:         av_free(audio_size);
yading@11:         av_free(chunk_offset);
yading@11:         return AVERROR(ENOMEM);
yading@11:     }
yading@11: 
yading@11:     /** read offset and size tables */
yading@11:     for(i=0; i < frame_count;i++)
yading@11:         chunk_size[i] = avio_rl32(pb);
yading@11:     for(i=0; i < frame_count;i++)
yading@11:         chunk_offset[i] = avio_rl32(pb);
yading@11:     for(i=0; i < frame_count;i++)
yading@11:         audio_size[i] = avio_rl32(pb) & 0xFFFF;
yading@11: 
yading@11:     /** build the sample index */
yading@11:     for(i=0;i<frame_count;i++){
yading@11:         if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
yading@11:             ret = AVERROR_INVALIDDATA;
yading@11:             break;
yading@11:         }
yading@11: 
yading@11:         if(sound_rate && audio_size[i]){
yading@11:             av_add_index_entry(s->streams[1], chunk_offset[i],
yading@11:                 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
yading@11:             audio_frame_counter += audio_size[i] / channels;
yading@11:         }
yading@11:         av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
yading@11:             video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
yading@11:         ++video_frame_counter;
yading@11:     }
yading@11: 
yading@11: 
yading@11:     av_free(chunk_size);
yading@11:     av_free(audio_size);
yading@11:     av_free(chunk_offset);
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * read a single audio or video packet
yading@11:  * @param s demuxer context
yading@11:  * @param pkt the packet to be filled
yading@11:  * @return 0 on success, AVERROR otherwise
yading@11:  */
yading@11: static int rl2_read_packet(AVFormatContext *s,
yading@11:                             AVPacket *pkt)
yading@11: {
yading@11:     Rl2DemuxContext *rl2 = s->priv_data;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVIndexEntry *sample = NULL;
yading@11:     int i;
yading@11:     int ret = 0;
yading@11:     int stream_id = -1;
yading@11:     int64_t pos = INT64_MAX;
yading@11: 
yading@11:     /** check if there is a valid video or audio entry that can be used */
yading@11:     for(i=0; i<s->nb_streams; i++){
yading@11:         if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
yading@11:               && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
yading@11:             sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
yading@11:             pos= sample->pos;
yading@11:             stream_id= i;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     if(stream_id == -1)
yading@11:         return AVERROR_EOF;
yading@11: 
yading@11:     ++rl2->index_pos[stream_id];
yading@11: 
yading@11:     /** position the stream (will probably be there anyway) */
yading@11:     avio_seek(pb, sample->pos, SEEK_SET);
yading@11: 
yading@11:     /** fill the packet */
yading@11:     ret = av_get_packet(pb, pkt, sample->size);
yading@11:     if(ret != sample->size){
yading@11:         av_free_packet(pkt);
yading@11:         return AVERROR(EIO);
yading@11:     }
yading@11: 
yading@11:     pkt->stream_index = stream_id;
yading@11:     pkt->pts = sample->timestamp;
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * seek to a new timestamp
yading@11:  * @param s demuxer context
yading@11:  * @param stream_index index of the stream that should be seeked
yading@11:  * @param timestamp wanted timestamp
yading@11:  * @param flags direction and seeking mode
yading@11:  * @return 0 on success, -1 otherwise
yading@11:  */
yading@11: static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
yading@11: {
yading@11:     AVStream *st = s->streams[stream_index];
yading@11:     Rl2DemuxContext *rl2 = s->priv_data;
yading@11:     int i;
yading@11:     int index = av_index_search_timestamp(st, timestamp, flags);
yading@11:     if(index < 0)
yading@11:         return -1;
yading@11: 
yading@11:     rl2->index_pos[stream_index] = index;
yading@11:     timestamp = st->index_entries[index].timestamp;
yading@11: 
yading@11:     for(i=0; i < s->nb_streams; i++){
yading@11:         AVStream *st2 = s->streams[i];
yading@11:         index = av_index_search_timestamp(st2,
yading@11:                     av_rescale_q(timestamp, st->time_base, st2->time_base),
yading@11:                     flags | AVSEEK_FLAG_BACKWARD);
yading@11: 
yading@11:         if(index < 0)
yading@11:             index = 0;
yading@11: 
yading@11:         rl2->index_pos[i] = index;
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_rl2_demuxer = {
yading@11:     .name           = "rl2",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("RL2"),
yading@11:     .priv_data_size = sizeof(Rl2DemuxContext),
yading@11:     .read_probe     = rl2_probe,
yading@11:     .read_header    = rl2_read_header,
yading@11:     .read_packet    = rl2_read_packet,
yading@11:     .read_seek      = rl2_read_seek,
yading@11: };