mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-07 11:13:41 +02:00
174 lines
4.9 KiB
C
174 lines
4.9 KiB
C
/*
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* PDV demuxer
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* Copyright (c) 2023 Paul B Mahol
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "avformat.h"
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#include "internal.h"
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#define PDV_MAGIC "Playdate VID\x00\x00\x00\x00"
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typedef struct PDVDemuxContext {
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int current_frame;
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uint8_t *frame_flags;
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uint32_t *frame_offsets;
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} PDVDemuxContext;
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static int pdv_probe(const AVProbeData *pd)
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{
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if (strncmp(pd->buf, PDV_MAGIC, sizeof(PDV_MAGIC) - 1) == 0)
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return AVPROBE_SCORE_MAX;
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return 0;
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}
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static int pdv_read_header(AVFormatContext *s)
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{
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PDVDemuxContext *p = s->priv_data;
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AVIOContext *pb = s->pb;
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AVCodecParameters *par;
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AVStream *st;
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uint64_t start;
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uint32_t fps;
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avio_skip(pb, 16);
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st = avformat_new_stream(s, NULL);
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if (!st)
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return AVERROR(ENOMEM);
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par = st->codecpar;
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par->codec_type = AVMEDIA_TYPE_VIDEO;
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par->codec_id = AV_CODEC_ID_PDV;
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st->start_time = 0;
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st->duration =
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st->nb_frames = avio_rl16(pb);
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avio_skip(pb, 2);
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fps = avio_rl32(pb);
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st->avg_frame_rate = av_d2q(av_int2float(fps), INT_MAX);
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par->width = avio_rl16(pb);
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par->height = avio_rl16(pb);
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avpriv_set_pts_info(st, 64, st->avg_frame_rate.den, st->avg_frame_rate.num);
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p->current_frame = 0;
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p->frame_flags = av_calloc(st->nb_frames + 1, sizeof(*p->frame_flags));
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p->frame_offsets = av_calloc(st->nb_frames + 1, sizeof(*p->frame_offsets));
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if (!p->frame_flags || !p->frame_offsets)
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return AVERROR(ENOMEM);
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for (int n = 0; n <= st->nb_frames; n++) {
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const uint32_t entry = avio_rl32(pb);
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p->frame_flags[n] = entry & 3;
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p->frame_offsets[n] = entry >> 2;
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}
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start = avio_tell(pb);
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for (int n = 0; n < st->nb_frames; n++) {
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const uint64_t pos = start + p->frame_offsets[n];
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const int32_t size = p->frame_offsets[n+1] - p->frame_offsets[n];
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const int flags = p->frame_flags[n] & 1 ? AVINDEX_KEYFRAME : 0;
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if (p->frame_flags[n] == 0 || size <= 0 ||
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((pb->seekable & AVIO_SEEKABLE_NORMAL) && pos + size > avio_size(pb)))
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break;
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av_add_index_entry(st, pos, n, size, 0, flags);
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}
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return 0;
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}
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static int pdv_read_packet(AVFormatContext *s, AVPacket *pkt)
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{
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PDVDemuxContext *p = s->priv_data;
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AVStream *st = s->streams[0];
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FFStream *const sti = ffstream(st);
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AVIOContext *pb = s->pb;
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int32_t size, flags, ret;
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int64_t pos;
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if (p->current_frame >= st->nb_frames)
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return AVERROR_EOF;
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if (p->current_frame >= sti->nb_index_entries)
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return AVERROR(EIO);
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pos = sti->index_entries[p->current_frame].pos;
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flags = sti->index_entries[p->current_frame].flags;
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size = sti->index_entries[p->current_frame].size;
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avio_seek(pb, pos, SEEK_SET);
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if (avio_feof(pb) || ((pb->seekable & AVIO_SEEKABLE_NORMAL) && pos + size > avio_size(pb)) || size == 0)
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return AVERROR_EOF;
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ret = av_get_packet(pb, pkt, size);
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if (ret < 0)
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return ret;
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if (flags & AVINDEX_KEYFRAME)
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pkt->flags |= AV_PKT_FLAG_KEY;
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pkt->stream_index = 0;
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pkt->pts = p->current_frame++;
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pkt->duration = 1;
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return 0;
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}
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static int pdv_read_close(AVFormatContext *s)
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{
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PDVDemuxContext *p = s->priv_data;
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av_freep(&p->frame_flags);
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av_freep(&p->frame_offsets);
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return 0;
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}
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static int pdv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
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{
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PDVDemuxContext *p = s->priv_data;
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AVStream *st = s->streams[stream_index];
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int index = av_index_search_timestamp(st, timestamp, flags);
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if (index < 0)
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return -1;
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if (avio_seek(s->pb, ffstream(st)->index_entries[index].pos, SEEK_SET) < 0)
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return -1;
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p->current_frame = index;
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return 0;
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}
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const AVInputFormat ff_pdv_demuxer = {
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.name = "pdv",
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.long_name = NULL_IF_CONFIG_SMALL("PlayDate Video"),
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.priv_data_size = sizeof(PDVDemuxContext),
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.flags_internal = FF_FMT_INIT_CLEANUP,
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.read_probe = pdv_probe,
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.read_header = pdv_read_header,
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.read_packet = pdv_read_packet,
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.read_close = pdv_read_close,
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.read_seek = pdv_read_seek,
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.extensions = "pdv",
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};
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