configure: Drop unused helper function test_cflags_cpp()
[libav.git] / libavformat / c93.c
1 /*
2 * Interplay C93 demuxer
3 * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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;
29 uint8_t length;
30 uint8_t frames;
31 } C93BlockRecord;
32
33 typedef struct C93DemuxContext {
34 VocDecContext voc;
35
36 C93BlockRecord block_records[512];
37 int current_block;
38
39 uint32_t frame_offsets[32];
40 int current_frame;
41 int next_pkt_is_audio;
42
43 AVStream *audio;
44 } C93DemuxContext;
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
60 static int read_header(AVFormatContext *s)
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 */
80 s->ctx_flags |= AVFMTCTX_NOHEADER;
81
82 video = avformat_new_stream(s, NULL);
83 if (!video)
84 return AVERROR(ENOMEM);
85
86 video->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
87 video->codecpar->codec_id = AV_CODEC_ID_C93;
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
106 static int read_packet(AVFormatContext *s, AVPacket *pkt)
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);
123 c93->audio->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
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(EIO);
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
195 AVInputFormat ff_c93_demuxer = {
196 .name = "c93",
197 .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
198 .priv_data_size = sizeof(C93DemuxContext),
199 .read_probe = probe,
200 .read_header = read_header,
201 .read_packet = read_packet,
202 };