1/*
2 * RL2 Format Demuxer
3 * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * RL2 file demuxer
24 * @file
25 * @author Sascha Sommer (saschasommer@freenet.de)
26 * For more information regarding the RL2 file format, visit:
27 *   http://wiki.multimedia.cx/index.php?title=RL2
28 *
29 * extradata:
30 * 2 byte le initial drawing offset within 320x200 viewport
31 * 4 byte le number of used colors
32 * 256 * 3 bytes rgb palette
33 * optional background_frame
34 */
35
36#include "libavutil/intreadwrite.h"
37#include "avformat.h"
38
39#define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
40
41#define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
42#define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
43#define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
44
45typedef struct Rl2DemuxContext {
46    unsigned int index_pos[2];   ///< indexes in the sample tables
47} Rl2DemuxContext;
48
49
50/**
51 * check if the file is in rl2 format
52 * @param p probe buffer
53 * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
54 */
55static int rl2_probe(AVProbeData *p)
56{
57
58    if(AV_RB32(&p->buf[0]) != FORM_TAG)
59        return 0;
60
61    if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
62        AV_RB32(&p->buf[8]) != RLV3_TAG)
63        return 0;
64
65    return AVPROBE_SCORE_MAX;
66}
67
68/**
69 * read rl2 header data and setup the avstreams
70 * @param s demuxer context
71 * @param ap format parameters
72 * @return 0 on success, AVERROR otherwise
73 */
74static av_cold int rl2_read_header(AVFormatContext *s,
75                            AVFormatParameters *ap)
76{
77    ByteIOContext *pb = s->pb;
78    AVStream *st;
79    unsigned int frame_count;
80    unsigned int audio_frame_counter = 0;
81    unsigned int video_frame_counter = 0;
82    unsigned int back_size;
83    int data_size;
84    unsigned short encoding_method;
85    unsigned short sound_rate;
86    unsigned short rate;
87    unsigned short channels;
88    unsigned short def_sound_size;
89    unsigned int signature;
90    unsigned int pts_den = 11025; /* video only case */
91    unsigned int pts_num = 1103;
92    unsigned int* chunk_offset = NULL;
93    int* chunk_size = NULL;
94    int* audio_size = NULL;
95    int i;
96    int ret = 0;
97
98    url_fskip(pb,4);          /* skip FORM tag */
99    back_size = get_le32(pb); /** get size of the background frame */
100    signature = get_be32(pb);
101    data_size = get_be32(pb);
102    frame_count = get_le32(pb);
103
104    /* disallow back_sizes and frame_counts that may lead to overflows later */
105    if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
106        return AVERROR_INVALIDDATA;
107
108    encoding_method = get_le16(pb);
109    sound_rate = get_le16(pb);
110    rate = get_le16(pb);
111    channels = get_le16(pb);
112    def_sound_size = get_le16(pb);
113
114    /** setup video stream */
115    st = av_new_stream(s, 0);
116    if(!st)
117         return AVERROR(ENOMEM);
118
119    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
120    st->codec->codec_id = CODEC_ID_RL2;
121    st->codec->codec_tag = 0;  /* no fourcc */
122    st->codec->width = 320;
123    st->codec->height = 200;
124
125    /** allocate and fill extradata */
126    st->codec->extradata_size = EXTRADATA1_SIZE;
127
128    if(signature == RLV3_TAG && back_size > 0)
129        st->codec->extradata_size += back_size;
130
131    st->codec->extradata = av_mallocz(st->codec->extradata_size +
132                                          FF_INPUT_BUFFER_PADDING_SIZE);
133    if(!st->codec->extradata)
134        return AVERROR(ENOMEM);
135
136    if(get_buffer(pb,st->codec->extradata,st->codec->extradata_size) !=
137                      st->codec->extradata_size)
138        return AVERROR(EIO);
139
140    /** setup audio stream if present */
141    if(sound_rate){
142        pts_num = def_sound_size;
143        pts_den = rate;
144
145        st = av_new_stream(s, 0);
146        if (!st)
147            return AVERROR(ENOMEM);
148        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
149        st->codec->codec_id = CODEC_ID_PCM_U8;
150        st->codec->codec_tag = 1;
151        st->codec->channels = channels;
152        st->codec->bits_per_coded_sample = 8;
153        st->codec->sample_rate = rate;
154        st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
155            st->codec->bits_per_coded_sample;
156        st->codec->block_align = st->codec->channels *
157            st->codec->bits_per_coded_sample / 8;
158        av_set_pts_info(st,32,1,rate);
159    }
160
161    av_set_pts_info(s->streams[0], 32, pts_num, pts_den);
162
163    chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
164    audio_size =   av_malloc(frame_count * sizeof(uint32_t));
165    chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
166
167    if(!chunk_size || !audio_size || !chunk_offset){
168        av_free(chunk_size);
169        av_free(audio_size);
170        av_free(chunk_offset);
171        return AVERROR(ENOMEM);
172    }
173
174    /** read offset and size tables */
175    for(i=0; i < frame_count;i++)
176        chunk_size[i] = get_le32(pb);
177    for(i=0; i < frame_count;i++)
178        chunk_offset[i] = get_le32(pb);
179    for(i=0; i < frame_count;i++)
180        audio_size[i] = get_le32(pb) & 0xFFFF;
181
182    /** build the sample index */
183    for(i=0;i<frame_count;i++){
184        if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
185            ret = AVERROR_INVALIDDATA;
186            break;
187        }
188
189        if(sound_rate && audio_size[i]){
190            av_add_index_entry(s->streams[1], chunk_offset[i],
191                audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
192            audio_frame_counter += audio_size[i] / channels;
193        }
194        av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
195            video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
196        ++video_frame_counter;
197    }
198
199
200    av_free(chunk_size);
201    av_free(audio_size);
202    av_free(chunk_offset);
203
204    return ret;
205}
206
207/**
208 * read a single audio or video packet
209 * @param s demuxer context
210 * @param pkt the packet to be filled
211 * @return 0 on success, AVERROR otherwise
212 */
213static int rl2_read_packet(AVFormatContext *s,
214                            AVPacket *pkt)
215{
216    Rl2DemuxContext *rl2 = s->priv_data;
217    ByteIOContext *pb = s->pb;
218    AVIndexEntry *sample = NULL;
219    int i;
220    int ret = 0;
221    int stream_id = -1;
222    int64_t pos = INT64_MAX;
223
224    /** check if there is a valid video or audio entry that can be used */
225    for(i=0; i<s->nb_streams; i++){
226        if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
227              && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
228            sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
229            pos= sample->pos;
230            stream_id= i;
231        }
232    }
233
234    if(stream_id == -1)
235        return AVERROR(EIO);
236
237    ++rl2->index_pos[stream_id];
238
239    /** position the stream (will probably be there anyway) */
240    url_fseek(pb, sample->pos, SEEK_SET);
241
242    /** fill the packet */
243    ret = av_get_packet(pb, pkt, sample->size);
244    if(ret != sample->size){
245        av_free_packet(pkt);
246        return AVERROR(EIO);
247    }
248
249    pkt->stream_index = stream_id;
250    pkt->pts = sample->timestamp;
251
252    return ret;
253}
254
255/**
256 * seek to a new timestamp
257 * @param s demuxer context
258 * @param stream_index index of the stream that should be seeked
259 * @param timestamp wanted timestamp
260 * @param flags direction and seeking mode
261 * @return 0 on success, -1 otherwise
262 */
263static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
264{
265    AVStream *st = s->streams[stream_index];
266    Rl2DemuxContext *rl2 = s->priv_data;
267    int i;
268    int index = av_index_search_timestamp(st, timestamp, flags);
269    if(index < 0)
270        return -1;
271
272    rl2->index_pos[stream_index] = index;
273    timestamp = st->index_entries[index].timestamp;
274
275    for(i=0; i < s->nb_streams; i++){
276        AVStream *st2 = s->streams[i];
277        index = av_index_search_timestamp(st2,
278                    av_rescale_q(timestamp, st->time_base, st2->time_base),
279                    flags | AVSEEK_FLAG_BACKWARD);
280
281        if(index < 0)
282            index = 0;
283
284        rl2->index_pos[i] = index;
285    }
286
287    return 0;
288}
289
290AVInputFormat rl2_demuxer = {
291    "rl2",
292    NULL_IF_CONFIG_SMALL("RL2 format"),
293    sizeof(Rl2DemuxContext),
294    rl2_probe,
295    rl2_read_header,
296    rl2_read_packet,
297    NULL,
298    rl2_read_seek,
299};
300
301