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/*
* PDV demuxer
* Copyright (c) 2023 Paul B Mahol
*
* 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"
#define PDV_MAGIC "Playdate VID\x00\x00\x00\x00"
typedef struct PDVDemuxContext {
int current_frame;
uint8_t *frame_flags;
uint32_t *frame_offsets;
} PDVDemuxContext;
static int pdv_probe(const AVProbeData *pd)
{
if (strncmp(pd->buf, PDV_MAGIC, sizeof(PDV_MAGIC) - 1) == 0)
return AVPROBE_SCORE_MAX;
return 0;
}
static int pdv_read_header(AVFormatContext *s)
{
PDVDemuxContext *p = s->priv_data;
AVIOContext *pb = s->pb;
AVCodecParameters *par;
AVStream *st;
uint64_t start;
uint32_t fps;
avio_skip(pb, 16);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
par = st->codecpar;
par->codec_type = AVMEDIA_TYPE_VIDEO;
par->codec_id = AV_CODEC_ID_PDV;
st->start_time = 0;
st->duration =
st->nb_frames = avio_rl16(pb);
avio_skip(pb, 2);
fps = avio_rl32(pb);
st->avg_frame_rate = av_d2q(av_int2float(fps), INT_MAX);
par->width = avio_rl16(pb);
par->height = avio_rl16(pb);
avpriv_set_pts_info(st, 64, st->avg_frame_rate.den, st->avg_frame_rate.num);
p->current_frame = 0;
p->frame_flags = av_calloc(st->nb_frames + 1, sizeof(*p->frame_flags));
p->frame_offsets = av_calloc(st->nb_frames + 1, sizeof(*p->frame_offsets));
if (!p->frame_flags || !p->frame_offsets)
return AVERROR(ENOMEM);
for (int n = 0; n <= st->nb_frames; n++) {
const uint32_t entry = avio_rl32(pb);
p->frame_flags[n] = entry & 3;
p->frame_offsets[n] = entry >> 2;
}
start = avio_tell(pb);
for (int n = 0; n < st->nb_frames; n++) {
const uint64_t pos = start + p->frame_offsets[n];
const int32_t size = p->frame_offsets[n+1] - p->frame_offsets[n];
const int flags = p->frame_flags[n] & 1 ? AVINDEX_KEYFRAME : 0;
if (p->frame_flags[n] == 0 || size <= 0 ||
((pb->seekable & AVIO_SEEKABLE_NORMAL) && pos + size > avio_size(pb)))
break;
av_add_index_entry(st, pos, n, size, 0, flags);
}
return 0;
}
static int pdv_read_packet(AVFormatContext *s, AVPacket *pkt)
{
PDVDemuxContext *p = s->priv_data;
AVStream *st = s->streams[0];
FFStream *const sti = ffstream(st);
AVIOContext *pb = s->pb;
int32_t size, flags, ret;
int64_t pos;
if (p->current_frame >= st->nb_frames)
return AVERROR_EOF;
if (p->current_frame >= sti->nb_index_entries)
return AVERROR(EIO);
pos = sti->index_entries[p->current_frame].pos;
flags = sti->index_entries[p->current_frame].flags;
size = sti->index_entries[p->current_frame].size;
avio_seek(pb, pos, SEEK_SET);
if (avio_feof(pb) || ((pb->seekable & AVIO_SEEKABLE_NORMAL) && pos + size > avio_size(pb)) || size == 0)
return AVERROR_EOF;
ret = av_get_packet(pb, pkt, size);
if (ret < 0)
return ret;
if (flags & AVINDEX_KEYFRAME)
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->stream_index = 0;
pkt->pts = p->current_frame++;
pkt->duration = 1;
return 0;
}
static int pdv_read_close(AVFormatContext *s)
{
PDVDemuxContext *p = s->priv_data;
av_freep(&p->frame_flags);
av_freep(&p->frame_offsets);
return 0;
}
static int pdv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
PDVDemuxContext *p = s->priv_data;
AVStream *st = s->streams[stream_index];
int index = av_index_search_timestamp(st, timestamp, flags);
if (index < 0)
return -1;
if (avio_seek(s->pb, ffstream(st)->index_entries[index].pos, SEEK_SET) < 0)
return -1;
p->current_frame = index;
return 0;
}
const AVInputFormat ff_pdv_demuxer = {
.name = "pdv",
.long_name = NULL_IF_CONFIG_SMALL("PlayDate Video"),
.priv_data_size = sizeof(PDVDemuxContext),
.flags_internal = FF_FMT_INIT_CLEANUP,
.read_probe = pdv_probe,
.read_header = pdv_read_header,
.read_packet = pdv_read_packet,
.read_close = pdv_read_close,
.read_seek = pdv_read_seek,
.extensions = "pdv",
};
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