| 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 | }; |