mirror of https://github.com/FFmpeg/FFmpeg.git
Paul B Mahol
2 years ago
parent
40bae5be5e
commit
dc2da568cf
5 changed files with 178 additions and 3 deletions
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/*
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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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