ffmpeg/libavformat/gdv.c

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/*
* Gremlin Digital Video demuxer
* Copyright (c) 2017 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 "libavutil/intreadwrite.h"
#include "avformat.h"
#include "avio.h"
#include "internal.h"
typedef struct GDVContext {
int is_first_video;
int is_audio;
int audio_size;
int audio_stream_index;
int video_stream_index;
unsigned pal[256];
} GDVContext;
static int gdv_read_probe(const AVProbeData *p)
{
if (AV_RL32(p->buf) == 0x29111994)
return AVPROBE_SCORE_MAX;
return 0;
}
static struct {
uint16_t id;
uint16_t width;
uint16_t height;
} FixedSize[] = {
{ 0, 320, 200},
{ 1, 640, 200},
{ 2, 320, 167},
{ 3, 320, 180},
{ 4, 320, 400},
{ 5, 320, 170},
{ 6, 160, 85},
{ 7, 160, 83},
{ 8, 160, 90},
{ 9, 280, 128},
{10, 320, 240},
{11, 320, 201},
{16, 640, 400},
{17, 640, 200},
{18, 640, 180},
{19, 640, 167},
{20, 640, 170},
{21, 320, 240}
};
static int gdv_read_header(AVFormatContext *ctx)
{
GDVContext *gdv = ctx->priv_data;
AVIOContext *pb = ctx->pb;
AVStream *vst, *ast;
unsigned fps, snd_flags, vid_depth, size_id;
avio_skip(pb, 4);
size_id = avio_rl16(pb);
vst = avformat_new_stream(ctx, 0);
if (!vst)
return AVERROR(ENOMEM);
vst->start_time = 0;
vst->duration =
vst->nb_frames = avio_rl16(pb);
fps = avio_rl16(pb);
if (!fps)
return AVERROR_INVALIDDATA;
snd_flags = avio_rl16(pb);
if (snd_flags & 1) {
ast = avformat_new_stream(ctx, 0);
if (!ast)
return AVERROR(ENOMEM);
ast->start_time = 0;
ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
ast->codecpar->codec_tag = 0;
ast->codecpar->sample_rate = avio_rl16(pb);
ast->codecpar->channels = 1 + !!(snd_flags & 2);
if (snd_flags & 8) {
ast->codecpar->codec_id = AV_CODEC_ID_GREMLIN_DPCM;
} else {
ast->codecpar->codec_id = (snd_flags & 4) ? AV_CODEC_ID_PCM_S16LE : AV_CODEC_ID_PCM_U8;
}
avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);
gdv->audio_size = (ast->codecpar->sample_rate / fps) *
ast->codecpar->channels * (1 + !!(snd_flags & 4)) / (1 + !!(snd_flags & 8));
gdv->is_audio = 1;
} else {
avio_skip(pb, 2);
}
vid_depth = avio_rl16(pb);
avio_skip(pb, 4);
vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
vst->codecpar->codec_id = AV_CODEC_ID_GDV;
vst->codecpar->codec_tag = 0;
vst->codecpar->width = avio_rl16(pb);
vst->codecpar->height = avio_rl16(pb);
if (vst->codecpar->width == 0 || vst->codecpar->height == 0) {
int i;
for (i = 0; i < FF_ARRAY_ELEMS(FixedSize) - 1; i++) {
if (FixedSize[i].id == size_id)
break;
}
vst->codecpar->width = FixedSize[i].width;
vst->codecpar->height = FixedSize[i].height;
}
avpriv_set_pts_info(vst, 64, 1, fps);
if (vid_depth & 1) {
int i;
for (i = 0; i < 256; i++) {
unsigned r = avio_r8(pb);
unsigned g = avio_r8(pb);
unsigned b = avio_r8(pb);
gdv->pal[i] = 0xFFU << 24 | r << 18 | g << 10 | b << 2;
}
}
gdv->is_first_video = 1;
return 0;
}
static int gdv_read_packet(AVFormatContext *ctx, AVPacket *pkt)
{
GDVContext *gdv = ctx->priv_data;
AVIOContext *pb = ctx->pb;
int ret;
if (avio_feof(pb))
return pb->error ? pb->error : AVERROR_EOF;
if (gdv->audio_size && gdv->is_audio) {
ret = av_get_packet(pb, pkt, gdv->audio_size);
if (ret < 0)
return ret;
pkt->stream_index = 1;
gdv->is_audio = 0;
} else {
uint8_t *pal;
if (avio_rl16(pb) != 0x1305)
return AVERROR_INVALIDDATA;
ret = av_get_packet(pb, pkt, 4 + avio_rl16(pb));
if (ret < 0)
return ret;
pkt->stream_index = 0;
gdv->is_audio = 1;
if (gdv->is_first_video) {
pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,
AVPALETTE_SIZE);
if (!pal) {
return AVERROR(ENOMEM);
}
memcpy(pal, gdv->pal, AVPALETTE_SIZE);
pkt->flags |= AV_PKT_FLAG_KEY;
gdv->is_first_video = 0;
}
}
return 0;
}
const AVInputFormat ff_gdv_demuxer = {
.name = "gdv",
.long_name = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
.priv_data_size = sizeof(GDVContext),
.read_probe = gdv_read_probe,
.read_header = gdv_read_header,
.read_packet = gdv_read_packet,
};