diff options
Diffstat (limited to 'ffmpeg/libavformat/c93.c')
| -rw-r--r-- | ffmpeg/libavformat/c93.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/ffmpeg/libavformat/c93.c b/ffmpeg/libavformat/c93.c new file mode 100644 index 0000000..93a61be --- /dev/null +++ b/ffmpeg/libavformat/c93.c @@ -0,0 +1,202 @@ +/* + * Interplay C93 demuxer + * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com> + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "avformat.h" +#include "internal.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) +{ + 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 = AV_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 }; + avpriv_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 = ff_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_EOF; + 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, +}; |