blob: b1a245a3cfe866f9882b52431ac69191e7747055
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; |
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_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 | |
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 | }; |
203 |