| /* |
| * 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 "voc.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) |
| { |
| if (p->buf[0] == 0x01 && p->buf[1] == 0x00 && |
| p->buf[4] == 0x01 + p->buf[2] && |
| p->buf[8] == p->buf[4] + p->buf[6] && |
| p->buf[12] == p->buf[8] + p->buf[10]) |
| return AVPROBE_SCORE_MAX; |
| |
| return 0; |
| } |
| |
| static int read_header(AVFormatContext *s, |
| AVFormatParameters *ap) |
| { |
| AVStream *video; |
| ByteIOContext *pb = s->pb; |
| C93DemuxContext *c93 = s->priv_data; |
| int i; |
| int framecount = 0; |
| |
| for (i = 0; i < 512; i++) { |
| c93->block_records[i].index = get_le16(pb); |
| c93->block_records[i].length = get_byte(pb); |
| c93->block_records[i].frames = get_byte(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 = av_new_stream(s, 0); |
| if (!video) |
| return AVERROR(ENOMEM); |
| |
| video->codec->codec_type = CODEC_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 }; |
| video->time_base = (AVRational) { 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) |
| { |
| ByteIOContext *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 = get_le16(pb); |
| if (datasize > 42) { |
| if (!c93->audio) { |
| c93->audio = av_new_stream(s, 1); |
| if (!c93->audio) |
| return AVERROR(ENOMEM); |
| c93->audio->codec->codec_type = CODEC_TYPE_AUDIO; |
| } |
| url_fskip(pb, 26); /* VOC header */ |
| ret = voc_get_packet(s, pkt, c93->audio, datasize - 26); |
| if (ret > 0) { |
| pkt->stream_index = 1; |
| pkt->flags |= 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) { |
| url_fseek(pb, br->index * 2048, SEEK_SET); |
| for (i = 0; i < 32; i++) { |
| c93->frame_offsets[i] = get_le32(pb); |
| } |
| } |
| |
| url_fseek(pb,br->index * 2048 + |
| c93->frame_offsets[c93->current_frame], SEEK_SET); |
| datasize = get_le16(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 = get_buffer(pb, pkt->data + 1, datasize); |
| if (ret < datasize) { |
| ret = AVERROR(EIO); |
| goto fail; |
| } |
| |
| datasize = get_le16(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 = get_buffer(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 |= PKT_FLAG_KEY; |
| pkt->data[0] |= C93_FIRST_FRAME; |
| } |
| return 0; |
| |
| fail: |
| av_free_packet(pkt); |
| return ret; |
| } |
| |
| AVInputFormat c93_demuxer = { |
| "c93", |
| NULL_IF_CONFIG_SMALL("Interplay C93"), |
| sizeof(C93DemuxContext), |
| probe, |
| read_header, |
| read_packet, |
| }; |