/* * Interplay C93 demuxer * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com> * * This file is part of Libav. * * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avformat.h" #include "voc.h" #include "libavutil/intreadwrite.h" typedef struct { uint16_t index; uint8_t length; uint8_t frames; } C93BlockRecord; typedef struct { VocDecContext voc; C93BlockRecord block_records[512]; int current_block; uint32_t frame_offsets[32]; int current_frame; int next_pkt_is_audio; AVStream *audio; } C93DemuxContext; static int probe(AVProbeData *p) { int i; int index = 1; if (p->buf_size < 16) return 0; for (i = 0; i < 16; i += 4) { if (AV_RL16(p->buf + i) != index || !p->buf[i + 2] || !p->buf[i + 3]) return 0; index += p->buf[i + 2]; } return AVPROBE_SCORE_MAX; } static int read_header(AVFormatContext *s, AVFormatParameters *ap) { AVStream *video; AVIOContext *pb = s->pb; C93DemuxContext *c93 = s->priv_data; int i; int framecount = 0; for (i = 0; i < 512; i++) { c93->block_records[i].index = avio_rl16(pb); c93->block_records[i].length = avio_r8(pb); c93->block_records[i].frames = avio_r8(pb); if (c93->block_records[i].frames > 32) { av_log(s, AV_LOG_ERROR, "too many frames in block\n"); return AVERROR_INVALIDDATA; } framecount += c93->block_records[i].frames; } /* Audio streams are added if audio packets are found */ s->ctx_flags |= AVFMTCTX_NOHEADER; video = avformat_new_stream(s, NULL); if (!video) return AVERROR(ENOMEM); video->codec->codec_type = AVMEDIA_TYPE_VIDEO; video->codec->codec_id = CODEC_ID_C93; video->codec->width = 320; video->codec->height = 192; /* 4:3 320x200 with 8 empty lines */ video->sample_aspect_ratio = (AVRational) { 5, 6 }; av_set_pts_info(video, 64, 2, 25); video->nb_frames = framecount; video->duration = framecount; video->start_time = 0; c93->current_block = 0; c93->current_frame = 0; c93->next_pkt_is_audio = 0; return 0; } #define C93_HAS_PALETTE 0x01 #define C93_FIRST_FRAME 0x02 static int read_packet(AVFormatContext *s, AVPacket *pkt) { AVIOContext *pb = s->pb; C93DemuxContext *c93 = s->priv_data; C93BlockRecord *br = &c93->block_records[c93->current_block]; int datasize; int ret, i; if (c93->next_pkt_is_audio) { c93->current_frame++; c93->next_pkt_is_audio = 0; datasize = avio_rl16(pb); if (datasize > 42) { if (!c93->audio) { c93->audio = avformat_new_stream(s, NULL); if (!c93->audio) return AVERROR(ENOMEM); c93->audio->codec->codec_type = AVMEDIA_TYPE_AUDIO; } avio_skip(pb, 26); /* VOC header */ ret = voc_get_packet(s, pkt, c93->audio, datasize - 26); if (ret > 0) { pkt->stream_index = 1; pkt->flags |= AV_PKT_FLAG_KEY; return ret; } } } if (c93->current_frame >= br->frames) { if (c93->current_block >= 511 || !br[1].length) return AVERROR(EIO); br++; c93->current_block++; c93->current_frame = 0; } if (c93->current_frame == 0) { avio_seek(pb, br->index * 2048, SEEK_SET); for (i = 0; i < 32; i++) { c93->frame_offsets[i] = avio_rl32(pb); } } avio_seek(pb,br->index * 2048 + c93->frame_offsets[c93->current_frame], SEEK_SET); datasize = avio_rl16(pb); /* video frame size */ ret = av_new_packet(pkt, datasize + 768 + 1); if (ret < 0) return ret; pkt->data[0] = 0; pkt->size = datasize + 1; ret = avio_read(pb, pkt->data + 1, datasize); if (ret < datasize) { ret = AVERROR(EIO); goto fail; } datasize = avio_rl16(pb); /* palette size */ if (datasize) { if (datasize != 768) { av_log(s, AV_LOG_ERROR, "invalid palette size %u\n", datasize); ret = AVERROR_INVALIDDATA; goto fail; } pkt->data[0] |= C93_HAS_PALETTE; ret = avio_read(pb, pkt->data + pkt->size, datasize); if (ret < datasize) { ret = AVERROR(EIO); goto fail; } pkt->size += 768; } pkt->stream_index = 0; c93->next_pkt_is_audio = 1; /* only the first frame is guaranteed to not reference previous frames */ if (c93->current_block == 0 && c93->current_frame == 0) { pkt->flags |= AV_PKT_FLAG_KEY; pkt->data[0] |= C93_FIRST_FRAME; } return 0; fail: av_free_packet(pkt); return ret; } AVInputFormat ff_c93_demuxer = { .name = "c93", .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"), .priv_data_size = sizeof(C93DemuxContext), .read_probe = probe, .read_header = read_header, .read_packet = read_packet, };