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/*
* 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"
#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 = av_new_stream(s, 0);
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 = av_new_stream(s, 1);
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,
};
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