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c93.c
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1 /*
2  * Interplay C93 demuxer
3  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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 #include "avformat.h"
23 #include "internal.h"
24 #include "voc.h"
25 #include "libavutil/intreadwrite.h"
26 
27 typedef struct C93BlockRecord {
28  uint16_t index;
32 
33 typedef struct C93DemuxContext {
35 
38 
39  uint32_t frame_offsets[32];
42 
45 
46 static int probe(AVProbeData *p)
47 {
48  int i;
49  int index = 1;
50  if (p->buf_size < 16)
51  return 0;
52  for (i = 0; i < 16; i += 4) {
53  if (AV_RL16(p->buf + i) != index || !p->buf[i + 2] || !p->buf[i + 3])
54  return 0;
55  index += p->buf[i + 2];
56  }
57  return AVPROBE_SCORE_MAX;
58 }
59 
61 {
62  AVStream *video;
63  AVIOContext *pb = s->pb;
64  C93DemuxContext *c93 = s->priv_data;
65  int i;
66  int framecount = 0;
67 
68  for (i = 0; i < 512; i++) {
69  c93->block_records[i].index = avio_rl16(pb);
70  c93->block_records[i].length = avio_r8(pb);
71  c93->block_records[i].frames = avio_r8(pb);
72  if (c93->block_records[i].frames > 32) {
73  av_log(s, AV_LOG_ERROR, "too many frames in block\n");
74  return AVERROR_INVALIDDATA;
75  }
76  framecount += c93->block_records[i].frames;
77  }
78 
79  /* Audio streams are added if audio packets are found */
81 
82  video = avformat_new_stream(s, NULL);
83  if (!video)
84  return AVERROR(ENOMEM);
85 
88  video->codecpar->width = 320;
89  video->codecpar->height = 192;
90  /* 4:3 320x200 with 8 empty lines */
91  video->sample_aspect_ratio = (AVRational) { 5, 6 };
92  avpriv_set_pts_info(video, 64, 2, 25);
93  video->nb_frames = framecount;
94  video->duration = framecount;
95  video->start_time = 0;
96 
97  c93->current_block = 0;
98  c93->current_frame = 0;
99  c93->next_pkt_is_audio = 0;
100  return 0;
101 }
102 
103 #define C93_HAS_PALETTE 0x01
104 #define C93_FIRST_FRAME 0x02
105 
107 {
108  AVIOContext *pb = s->pb;
109  C93DemuxContext *c93 = s->priv_data;
110  C93BlockRecord *br = &c93->block_records[c93->current_block];
111  int datasize;
112  int ret, i;
113 
114  if (c93->next_pkt_is_audio) {
115  c93->current_frame++;
116  c93->next_pkt_is_audio = 0;
117  datasize = avio_rl16(pb);
118  if (datasize > 42) {
119  if (!c93->audio) {
120  c93->audio = avformat_new_stream(s, NULL);
121  if (!c93->audio)
122  return AVERROR(ENOMEM);
124  }
125  avio_skip(pb, 26); /* VOC header */
126  ret = ff_voc_get_packet(s, pkt, c93->audio, datasize - 26);
127  if (ret > 0) {
128  pkt->stream_index = 1;
129  pkt->flags |= AV_PKT_FLAG_KEY;
130  return ret;
131  }
132  }
133  }
134  if (c93->current_frame >= br->frames) {
135  if (c93->current_block >= 511 || !br[1].length)
136  return AVERROR_EOF;
137  br++;
138  c93->current_block++;
139  c93->current_frame = 0;
140  }
141 
142  if (c93->current_frame == 0) {
143  avio_seek(pb, br->index * 2048, SEEK_SET);
144  for (i = 0; i < 32; i++) {
145  c93->frame_offsets[i] = avio_rl32(pb);
146  }
147  }
148 
149  avio_seek(pb,br->index * 2048 +
150  c93->frame_offsets[c93->current_frame], SEEK_SET);
151  datasize = avio_rl16(pb); /* video frame size */
152 
153  ret = av_new_packet(pkt, datasize + 768 + 1);
154  if (ret < 0)
155  return ret;
156  pkt->data[0] = 0;
157  pkt->size = datasize + 1;
158 
159  ret = avio_read(pb, pkt->data + 1, datasize);
160  if (ret < datasize) {
161  ret = AVERROR(EIO);
162  goto fail;
163  }
164 
165  datasize = avio_rl16(pb); /* palette size */
166  if (datasize) {
167  if (datasize != 768) {
168  av_log(s, AV_LOG_ERROR, "invalid palette size %u\n", datasize);
169  ret = AVERROR_INVALIDDATA;
170  goto fail;
171  }
172  pkt->data[0] |= C93_HAS_PALETTE;
173  ret = avio_read(pb, pkt->data + pkt->size, datasize);
174  if (ret < datasize) {
175  ret = AVERROR(EIO);
176  goto fail;
177  }
178  pkt->size += 768;
179  }
180  pkt->stream_index = 0;
181  c93->next_pkt_is_audio = 1;
182 
183  /* only the first frame is guaranteed to not reference previous frames */
184  if (c93->current_block == 0 && c93->current_frame == 0) {
185  pkt->flags |= AV_PKT_FLAG_KEY;
186  pkt->data[0] |= C93_FIRST_FRAME;
187  }
188  return 0;
189 
190  fail:
191  av_packet_unref(pkt);
192  return ret;
193 }
194 
196  .name = "c93",
197  .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
198  .priv_data_size = sizeof(C93DemuxContext),
199  .read_probe = probe,
202 };
uint32_t frame_offsets[32]
Definition: c93.c:39
#define NULL
Definition: coverity.c:32
static int probe(AVProbeData *p)
Definition: c93.c:46
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:147
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
Definition: voc_packet.c:27
uint8_t frames
Definition: c93.c:30
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4549
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3969
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:948
int size
Definition: avcodec.h:1601
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: c93.c:106
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:230
static int read_header(AVFormatContext *s)
Definition: c93.c:60
VocDecContext voc
Definition: c93.c:34
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:304
static AVPacket pkt
int ctx_flags
Flags signalling stream properties.
Definition: avformat.h:1379
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
Format I/O context.
Definition: avformat.h:1330
int next_pkt_is_audio
Definition: c93.c:41
uint8_t
int width
Video only.
Definition: avcodec.h:4035
#define AVFMTCTX_NOHEADER
signal that no header is present (streams are added dynamically)
Definition: avformat.h:1283
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4182
int current_frame
Definition: c93.c:40
uint8_t * data
Definition: avcodec.h:1600
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:604
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1632
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define C93_HAS_PALETTE
Definition: c93.c:103
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:726
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3965
#define fail()
Definition: checkasm.h:82
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1606
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:595
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:464
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:463
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
int current_block
Definition: c93.c:37
C93BlockRecord block_records[512]
Definition: c93.c:36
Stream structure.
Definition: avformat.h:881
AVStream * audio
Definition: c93.c:43
uint16_t index
Definition: c93.c:28
AVIOContext * pb
I/O context.
Definition: avformat.h:1372
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:567
int index
Definition: gxfenc.c:89
Rational number (pair of numerator and denominator).
Definition: rational.h:58
This structure contains the data a format has to probe a file.
Definition: avformat.h:461
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:935
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:473
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:710
Main libavformat public API header.
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:928
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:937
AVInputFormat ff_c93_demuxer
Definition: c93.c:195
void * priv_data
Format private data.
Definition: avformat.h:1358
#define C93_FIRST_FRAME
Definition: c93.c:104
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:662
AVCodecParameters * codecpar
Definition: avformat.h:1233
int stream_index
Definition: avcodec.h:1602
This structure stores compressed data.
Definition: avcodec.h:1577
uint8_t length
Definition: c93.c:29