2 * Interplay C93 demuxer
3 * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
5 * This file is part of FFmpeg.
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.
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.
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
32 voc_dec_context_t voc;
34 C93BlockRecord block_records[512];
37 uint32_t frame_offsets[32];
39 int next_pkt_is_audio;
44 static int probe(AVProbeData *p)
46 if (p->buf[0] == 0x01 && p->buf[1] == 0x00 &&
47 p->buf[4] == 0x01 + p->buf[2] &&
48 p->buf[8] == p->buf[4] + p->buf[6] &&
49 p->buf[12] == p->buf[8] + p->buf[10])
50 return AVPROBE_SCORE_MAX;
55 static int read_header(AVFormatContext *s,
56 AVFormatParameters *ap)
59 ByteIOContext *pb = s->pb;
60 C93DemuxContext *c93 = s->priv_data;
64 for (i = 0; i < 512; i++) {
65 c93->block_records[i].index = get_le16(pb);
66 c93->block_records[i].length = get_byte(pb);
67 c93->block_records[i].frames = get_byte(pb);
68 if (c93->block_records[i].frames > 32) {
69 av_log(s, AV_LOG_ERROR, "too many frames in block\n");
70 return AVERROR_INVALIDDATA;
72 framecount += c93->block_records[i].frames;
75 /* Audio streams are added if audio packets are found */
76 s->ctx_flags |= AVFMTCTX_NOHEADER;
78 video = av_new_stream(s, 0);
80 return AVERROR(ENOMEM);
82 video->codec->codec_type = CODEC_TYPE_VIDEO;
83 video->codec->codec_id = CODEC_ID_C93;
84 video->codec->width = 320;
85 video->codec->height = 192;
86 /* 4:3 320x200 with 8 empty lines */
87 video->codec->sample_aspect_ratio = (AVRational) { 5, 6 };
88 video->time_base = (AVRational) { 2, 25 };
89 video->nb_frames = framecount;
90 video->duration = framecount;
91 video->start_time = 0;
93 c93->current_block = 0;
94 c93->current_frame = 0;
95 c93->next_pkt_is_audio = 0;
99 #define C93_HAS_PALETTE 0x01
100 #define C93_FIRST_FRAME 0x02
102 static int read_packet(AVFormatContext *s, AVPacket *pkt)
104 ByteIOContext *pb = s->pb;
105 C93DemuxContext *c93 = s->priv_data;
106 C93BlockRecord *br = &c93->block_records[c93->current_block];
110 if (c93->next_pkt_is_audio) {
111 c93->current_frame++;
112 c93->next_pkt_is_audio = 0;
113 datasize = get_le16(pb);
116 c93->audio = av_new_stream(s, 1);
118 return AVERROR(ENOMEM);
119 c93->audio->codec->codec_type = CODEC_TYPE_AUDIO;
121 url_fskip(pb, 26); /* VOC header */
122 ret = voc_get_packet(s, pkt, c93->audio, datasize - 26);
124 pkt->stream_index = 1;
125 pkt->flags |= PKT_FLAG_KEY;
130 if (c93->current_frame >= br->frames) {
131 if (c93->current_block >= 511 || !br[1].length)
134 c93->current_block++;
135 c93->current_frame = 0;
138 if (c93->current_frame == 0) {
139 url_fseek(pb, br->index * 2048, SEEK_SET);
140 for (i = 0; i < 32; i++) {
141 c93->frame_offsets[i] = get_le32(pb);
145 url_fseek(pb,br->index * 2048 +
146 c93->frame_offsets[c93->current_frame], SEEK_SET);
147 datasize = get_le16(pb); /* video frame size */
149 ret = av_new_packet(pkt, datasize + 768 + 1);
153 pkt->size = datasize + 1;
155 ret = get_buffer(pb, pkt->data + 1, datasize);
156 if (ret < datasize) {
161 datasize = get_le16(pb); /* palette size */
163 if (datasize != 768) {
164 av_log(s, AV_LOG_ERROR, "invalid palette size %u\n", datasize);
165 ret = AVERROR_INVALIDDATA;
168 pkt->data[0] |= C93_HAS_PALETTE;
169 ret = get_buffer(pb, pkt->data + pkt->size, datasize);
170 if (ret < datasize) {
176 pkt->stream_index = 0;
177 c93->next_pkt_is_audio = 1;
179 /* only the first frame is guaranteed to not reference previous frames */
180 if (c93->current_block == 0 && c93->current_frame == 0) {
181 pkt->flags |= PKT_FLAG_KEY;
182 pkt->data[0] |= C93_FIRST_FRAME;
191 AVInputFormat c93_demuxer = {
194 sizeof(C93DemuxContext),