yading@11: /*
yading@11:  * Interplay C93 demuxer
yading@11:  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "voc.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: 
yading@11: typedef struct {
yading@11:     uint16_t index;
yading@11:     uint8_t length;
yading@11:     uint8_t frames;
yading@11: } C93BlockRecord;
yading@11: 
yading@11: typedef struct {
yading@11:     VocDecContext voc;
yading@11: 
yading@11:     C93BlockRecord block_records[512];
yading@11:     int current_block;
yading@11: 
yading@11:     uint32_t frame_offsets[32];
yading@11:     int current_frame;
yading@11:     int next_pkt_is_audio;
yading@11: 
yading@11:     AVStream *audio;
yading@11: } C93DemuxContext;
yading@11: 
yading@11: static int probe(AVProbeData *p)
yading@11: {
yading@11:     int i;
yading@11:     int index = 1;
yading@11:     if (p->buf_size < 16)
yading@11:         return 0;
yading@11:     for (i = 0; i < 16; i += 4) {
yading@11:         if (AV_RL16(p->buf + i) != index || !p->buf[i + 2] || !p->buf[i + 3])
yading@11:             return 0;
yading@11:         index += p->buf[i + 2];
yading@11:     }
yading@11:     return AVPROBE_SCORE_MAX;
yading@11: }
yading@11: 
yading@11: static int read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVStream *video;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     C93DemuxContext *c93 = s->priv_data;
yading@11:     int i;
yading@11:     int framecount = 0;
yading@11: 
yading@11:     for (i = 0; i < 512; i++) {
yading@11:         c93->block_records[i].index = avio_rl16(pb);
yading@11:         c93->block_records[i].length = avio_r8(pb);
yading@11:         c93->block_records[i].frames = avio_r8(pb);
yading@11:         if (c93->block_records[i].frames > 32) {
yading@11:             av_log(s, AV_LOG_ERROR, "too many frames in block\n");
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         framecount += c93->block_records[i].frames;
yading@11:     }
yading@11: 
yading@11:     /* Audio streams are added if audio packets are found */
yading@11:     s->ctx_flags |= AVFMTCTX_NOHEADER;
yading@11: 
yading@11:     video = avformat_new_stream(s, NULL);
yading@11:     if (!video)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     video->codec->codec_type = AVMEDIA_TYPE_VIDEO;
yading@11:     video->codec->codec_id = AV_CODEC_ID_C93;
yading@11:     video->codec->width = 320;
yading@11:     video->codec->height = 192;
yading@11:     /* 4:3 320x200 with 8 empty lines */
yading@11:     video->sample_aspect_ratio = (AVRational) { 5, 6 };
yading@11:     avpriv_set_pts_info(video, 64, 2, 25);
yading@11:     video->nb_frames = framecount;
yading@11:     video->duration = framecount;
yading@11:     video->start_time = 0;
yading@11: 
yading@11:     c93->current_block = 0;
yading@11:     c93->current_frame = 0;
yading@11:     c93->next_pkt_is_audio = 0;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: #define C93_HAS_PALETTE 0x01
yading@11: #define C93_FIRST_FRAME 0x02
yading@11: 
yading@11: static int read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     C93DemuxContext *c93 = s->priv_data;
yading@11:     C93BlockRecord *br = &c93->block_records[c93->current_block];
yading@11:     int datasize;
yading@11:     int ret, i;
yading@11: 
yading@11:     if (c93->next_pkt_is_audio) {
yading@11:         c93->current_frame++;
yading@11:         c93->next_pkt_is_audio = 0;
yading@11:         datasize = avio_rl16(pb);
yading@11:         if (datasize > 42) {
yading@11:             if (!c93->audio) {
yading@11:                 c93->audio = avformat_new_stream(s, NULL);
yading@11:                 if (!c93->audio)
yading@11:                     return AVERROR(ENOMEM);
yading@11:                 c93->audio->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:             }
yading@11:             avio_skip(pb, 26); /* VOC header */
yading@11:             ret = ff_voc_get_packet(s, pkt, c93->audio, datasize - 26);
yading@11:             if (ret > 0) {
yading@11:                 pkt->stream_index = 1;
yading@11:                 pkt->flags |= AV_PKT_FLAG_KEY;
yading@11:                 return ret;
yading@11:             }
yading@11:         }
yading@11:     }
yading@11:     if (c93->current_frame >= br->frames) {
yading@11:         if (c93->current_block >= 511 || !br[1].length)
yading@11:             return AVERROR_EOF;
yading@11:         br++;
yading@11:         c93->current_block++;
yading@11:         c93->current_frame = 0;
yading@11:     }
yading@11: 
yading@11:     if (c93->current_frame == 0) {
yading@11:         avio_seek(pb, br->index * 2048, SEEK_SET);
yading@11:         for (i = 0; i < 32; i++) {
yading@11:             c93->frame_offsets[i] = avio_rl32(pb);
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     avio_seek(pb,br->index * 2048 +
yading@11:             c93->frame_offsets[c93->current_frame], SEEK_SET);
yading@11:     datasize = avio_rl16(pb); /* video frame size */
yading@11: 
yading@11:     ret = av_new_packet(pkt, datasize + 768 + 1);
yading@11:     if (ret < 0)
yading@11:         return ret;
yading@11:     pkt->data[0] = 0;
yading@11:     pkt->size = datasize + 1;
yading@11: 
yading@11:     ret = avio_read(pb, pkt->data + 1, datasize);
yading@11:     if (ret < datasize) {
yading@11:         ret = AVERROR(EIO);
yading@11:         goto fail;
yading@11:     }
yading@11: 
yading@11:     datasize = avio_rl16(pb); /* palette size */
yading@11:     if (datasize) {
yading@11:         if (datasize != 768) {
yading@11:             av_log(s, AV_LOG_ERROR, "invalid palette size %u\n", datasize);
yading@11:             ret = AVERROR_INVALIDDATA;
yading@11:             goto fail;
yading@11:         }
yading@11:         pkt->data[0] |= C93_HAS_PALETTE;
yading@11:         ret = avio_read(pb, pkt->data + pkt->size, datasize);
yading@11:         if (ret < datasize) {
yading@11:             ret = AVERROR(EIO);
yading@11:             goto fail;
yading@11:         }
yading@11:         pkt->size += 768;
yading@11:     }
yading@11:     pkt->stream_index = 0;
yading@11:     c93->next_pkt_is_audio = 1;
yading@11: 
yading@11:     /* only the first frame is guaranteed to not reference previous frames */
yading@11:     if (c93->current_block == 0 && c93->current_frame == 0) {
yading@11:         pkt->flags |= AV_PKT_FLAG_KEY;
yading@11:         pkt->data[0] |= C93_FIRST_FRAME;
yading@11:     }
yading@11:     return 0;
yading@11: 
yading@11:     fail:
yading@11:     av_free_packet(pkt);
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_c93_demuxer = {
yading@11:     .name           = "c93",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("Interplay C93"),
yading@11:     .priv_data_size = sizeof(C93DemuxContext),
yading@11:     .read_probe     = probe,
yading@11:     .read_header    = read_header,
yading@11:     .read_packet    = read_packet,
yading@11: };