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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 { | |
28 | uint16_t index; | |
29 | uint8_t length; | |
30 | uint8_t frames; | |
31 | } C93BlockRecord; | |
32 | ||
33 | typedef struct { | |
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->codec->codec_type = AVMEDIA_TYPE_VIDEO; | |
87 | video->codec->codec_id = AV_CODEC_ID_C93; | |
88 | video->codec->width = 320; | |
89 | video->codec->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->codec->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_free_packet(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 | }; |