2 * Gremlin Digital Video demuxer
3 * Copyright (c) 2017 Paul B Mahol
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/intreadwrite.h"
28 typedef struct GDVContext {
32 int audio_stream_index;
33 int video_stream_index;
37 static int gdv_read_probe(AVProbeData *p)
39 if (AV_RL32(p->buf) == 0x29111994)
40 return AVPROBE_SCORE_MAX;
45 static int gdv_read_header(AVFormatContext *ctx)
47 GDVContext *gdv = ctx->priv_data;
48 AVIOContext *pb = ctx->pb;
50 unsigned fps, snd_flags, vid_depth;
54 vst = avformat_new_stream(ctx, 0);
56 return AVERROR(ENOMEM);
60 vst->nb_frames = avio_rl16(pb);
63 snd_flags = avio_rl16(pb);
65 ast = avformat_new_stream(ctx, 0);
67 return AVERROR(ENOMEM);
70 ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
71 ast->codecpar->codec_tag = 0;
72 ast->codecpar->sample_rate = avio_rl16(pb);
73 ast->codecpar->channels = 1 + !!(snd_flags & 2);
75 ast->codecpar->codec_id = AV_CODEC_ID_GREMLIN_DPCM;
77 ast->codecpar->codec_id = (snd_flags & 4) ? AV_CODEC_ID_PCM_S16LE : AV_CODEC_ID_PCM_U8;
80 avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);
81 gdv->audio_size = (ast->codecpar->sample_rate / fps) *
82 ast->codecpar->channels * (1 + !!(snd_flags & 4)) / (1 + !!(snd_flags & 8));
85 vid_depth = avio_rl16(pb);
88 vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
89 vst->codecpar->codec_id = AV_CODEC_ID_GDV;
90 vst->codecpar->codec_tag = 0;
91 vst->codecpar->width = avio_rl16(pb);
92 vst->codecpar->height = avio_rl16(pb);
94 avpriv_set_pts_info(vst, 64, 1, fps);
99 for (i = 0; i < 256; i++) {
100 unsigned r = avio_r8(pb);
101 unsigned g = avio_r8(pb);
102 unsigned b = avio_r8(pb);
103 gdv->pal[i] = 0xFF << 24 | r << 18 | g << 10 | b << 2;
107 gdv->is_first_video = 1;
112 static int gdv_read_packet(AVFormatContext *ctx, AVPacket *pkt)
114 GDVContext *gdv = ctx->priv_data;
115 AVIOContext *pb = ctx->pb;
119 return pb->error ? pb->error : AVERROR_EOF;
121 if (gdv->audio_size && gdv->is_audio) {
122 ret = av_get_packet(pb, pkt, gdv->audio_size);
125 pkt->stream_index = 1;
130 if (avio_rl16(pb) != 0x1305)
131 return AVERROR_INVALIDDATA;
132 ret = av_get_packet(pb, pkt, 4 + avio_rl16(pb));
135 pkt->stream_index = 0;
138 if (gdv->is_first_video) {
139 pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
142 av_packet_unref(pkt);
143 return AVERROR(ENOMEM);
145 memcpy(pal, gdv->pal, AVPALETTE_SIZE);
146 pkt->flags |= AV_PKT_FLAG_KEY;
147 gdv->is_first_video = 0;
154 AVInputFormat ff_gdv_demuxer = {
156 .long_name = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
157 .priv_data_size = sizeof(GDVContext),
158 .read_probe = gdv_read_probe,
159 .read_header = gdv_read_header,
160 .read_packet = gdv_read_packet,