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ffmpeg/libavformat/lxfdec.c

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/*
* LXF demuxer
* Copyright (c) 2010 Tomas Härdin
*
* 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 "libavcodec/bytestream.h"
#include "avformat.h"
#include "internal.h"
#define LXF_MAX_PACKET_HEADER_SIZE 256
#define LXF_HEADER_DATA_SIZE 120
#define LXF_IDENT "LEITCH\0"
#define LXF_IDENT_LENGTH 8
#define LXF_SAMPLERATE 48000
static const AVCodecTag lxf_tags[] = {
{ AV_CODEC_ID_MJPEG, 0 },
{ AV_CODEC_ID_MPEG1VIDEO, 1 },
{ AV_CODEC_ID_MPEG2VIDEO, 2 }, //MpMl, 4:2:0
{ AV_CODEC_ID_MPEG2VIDEO, 3 }, //MpPl, 4:2:2
{ AV_CODEC_ID_DVVIDEO, 4 }, //DV25
{ AV_CODEC_ID_DVVIDEO, 5 }, //DVCPRO
{ AV_CODEC_ID_DVVIDEO, 6 }, //DVCPRO50
{ AV_CODEC_ID_RAWVIDEO, 7 }, //AV_PIX_FMT_ARGB, where alpha is used for chroma keying
{ AV_CODEC_ID_RAWVIDEO, 8 }, //16-bit chroma key
{ AV_CODEC_ID_MPEG2VIDEO, 9 }, //4:2:2 CBP ("Constrained Bytes per Gop")
{ AV_CODEC_ID_NONE, 0 },
};
typedef struct {
int channels; ///< number of audio channels. zero means no audio
int frame_number; ///< current video frame
uint32_t video_format, packet_type, extended_size;
} LXFDemuxContext;
static int lxf_probe(AVProbeData *p)
{
if (!memcmp(p->buf, LXF_IDENT, LXF_IDENT_LENGTH))
return AVPROBE_SCORE_MAX;
return 0;
}
/**
* Verify the checksum of an LXF packet header
*
* @param[in] header the packet header to check
* @return zero if the checksum is OK, non-zero otherwise
*/
static int check_checksum(const uint8_t *header, int size)
{
int x;
uint32_t sum = 0;
for (x = 0; x < size; x += 4)
sum += AV_RL32(&header[x]);
return sum;
}
/**
* Read input until we find the next ident. If found, copy it to the header buffer
*
* @param[out] header where to copy the ident to
* @return 0 if an ident was found, < 0 on I/O error
*/
static int sync(AVFormatContext *s, uint8_t *header)
{
uint8_t buf[LXF_IDENT_LENGTH];
int ret;
if ((ret = avio_read(s->pb, buf, LXF_IDENT_LENGTH)) != LXF_IDENT_LENGTH)
return ret < 0 ? ret : AVERROR_EOF;
while (memcmp(buf, LXF_IDENT, LXF_IDENT_LENGTH)) {
if (url_feof(s->pb))
return AVERROR_EOF;
memmove(buf, &buf[1], LXF_IDENT_LENGTH-1);
buf[LXF_IDENT_LENGTH-1] = avio_r8(s->pb);
}
memcpy(header, LXF_IDENT, LXF_IDENT_LENGTH);
return 0;
}
/**
* Read and checksum the next packet header
*
* @return the size of the payload following the header or < 0 on failure
*/
static int get_packet_header(AVFormatContext *s)
{
LXFDemuxContext *lxf = s->priv_data;
AVIOContext *pb = s->pb;
int track_size, samples, ret;
uint32_t version, audio_format, header_size, channels, tmp;
AVStream *st;
uint8_t header[LXF_MAX_PACKET_HEADER_SIZE];
const uint8_t *p;
//find and read the ident
if ((ret = sync(s, header)) < 0)
return ret;
ret = avio_read(pb, header + LXF_IDENT_LENGTH, 8);
if (ret != 8)
return ret < 0 ? ret : AVERROR_EOF;
p = header + LXF_IDENT_LENGTH;
version = bytestream_get_le32(&p);
header_size = bytestream_get_le32(&p);
if (version > 1)
avpriv_request_sample(s, "format version %i", version);
if (header_size < (version ? 72 : 60) ||
header_size > LXF_MAX_PACKET_HEADER_SIZE ||
(header_size & 3)) {
av_log(s, AV_LOG_ERROR, "Invalid header size 0x%x\n", header_size);
return AVERROR_INVALIDDATA;
}
//read the rest of the packet header
if ((ret = avio_read(pb, header + (p - header),
header_size - (p - header))) !=
header_size - (p - header)) {
return ret < 0 ? ret : AVERROR_EOF;
}
if (check_checksum(header, header_size))
av_log(s, AV_LOG_ERROR, "checksum error\n");
lxf->packet_type = bytestream_get_le32(&p);
p += version ? 20 : 12;
lxf->extended_size = 0;
switch (lxf->packet_type) {
case 0:
//video
lxf->video_format = bytestream_get_le32(&p);
ret = bytestream_get_le32(&p);
//skip VBI data and metadata
avio_skip(pb, (int64_t)(uint32_t)AV_RL32(p + 4) +
(int64_t)(uint32_t)AV_RL32(p + 12));
break;
case 1:
//audio
if (!s->streams || !(st = s->streams[1])) {
av_log(s, AV_LOG_INFO, "got audio packet, but no audio stream present\n");
break;
}
if (version == 0) p += 8;
audio_format = bytestream_get_le32(&p);
channels = bytestream_get_le32(&p);
track_size = bytestream_get_le32(&p);
//set codec based on specified audio bitdepth
//we only support tightly packed 16-, 20-, 24- and 32-bit PCM at the moment
st->codec->bits_per_coded_sample = (audio_format >> 6) & 0x3F;
if (st->codec->bits_per_coded_sample != (audio_format & 0x3F)) {
av_log(s, AV_LOG_WARNING, "only tightly packed PCM currently supported\n");
return AVERROR_PATCHWELCOME;
}
switch (st->codec->bits_per_coded_sample) {
case 16: st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
case 20: st->codec->codec_id = AV_CODEC_ID_PCM_LXF; break;
case 24: st->codec->codec_id = AV_CODEC_ID_PCM_S24LE_PLANAR; break;
case 32: st->codec->codec_id = AV_CODEC_ID_PCM_S32LE_PLANAR; break;
default:
av_log(s, AV_LOG_WARNING,
"only 16-, 20-, 24- and 32-bit PCM currently supported\n");
return AVERROR_PATCHWELCOME;
}
samples = track_size * 8 / st->codec->bits_per_coded_sample;
//use audio packet size to determine video standard
//for NTSC we have one 8008-sample audio frame per five video frames
if (samples == LXF_SAMPLERATE * 5005 / 30000) {
avpriv_set_pts_info(s->streams[0], 64, 1001, 30000);
} else {
//assume PAL, but warn if we don't have 1920 samples
if (samples != LXF_SAMPLERATE / 25)
av_log(s, AV_LOG_WARNING,
"video doesn't seem to be PAL or NTSC. guessing PAL\n");
avpriv_set_pts_info(s->streams[0], 64, 1, 25);
}
//TODO: warning if track mask != (1 << channels) - 1?
ret = av_popcount(channels) * track_size;
break;
default:
tmp = bytestream_get_le32(&p);
ret = bytestream_get_le32(&p);
if (tmp == 1)
lxf->extended_size = bytestream_get_le32(&p);
break;
}
return ret;
}
static int lxf_read_header(AVFormatContext *s)
{
LXFDemuxContext *lxf = s->priv_data;
AVIOContext *pb = s->pb;
uint8_t header_data[LXF_HEADER_DATA_SIZE];
int ret;
AVStream *st;
uint32_t video_params, disk_params;
uint16_t record_date, expiration_date;
if ((ret = get_packet_header(s)) < 0)
return ret;
if (ret != LXF_HEADER_DATA_SIZE) {
av_log(s, AV_LOG_ERROR, "expected %d B size header, got %d\n",
LXF_HEADER_DATA_SIZE, ret);
return AVERROR_INVALIDDATA;
}
if ((ret = avio_read(pb, header_data, LXF_HEADER_DATA_SIZE)) != LXF_HEADER_DATA_SIZE)
return ret < 0 ? ret : AVERROR_EOF;
if (!(st = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
st->duration = AV_RL32(&header_data[32]);
video_params = AV_RL32(&header_data[40]);
record_date = AV_RL16(&header_data[56]);
expiration_date = AV_RL16(&header_data[58]);
disk_params = AV_RL32(&header_data[116]);
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->bit_rate = 1000000 * ((video_params >> 14) & 0xFF);
st->codec->codec_tag = video_params & 0xF;
st->codec->codec_id = ff_codec_get_id(lxf_tags, st->codec->codec_tag);
st->need_parsing = AVSTREAM_PARSE_HEADERS;
av_log(s, AV_LOG_DEBUG, "record: %x = %i-%02i-%02i\n",
record_date, 1900 + (record_date & 0x7F), (record_date >> 7) & 0xF,
(record_date >> 11) & 0x1F);
av_log(s, AV_LOG_DEBUG, "expire: %x = %i-%02i-%02i\n",
expiration_date, 1900 + (expiration_date & 0x7F), (expiration_date >> 7) & 0xF,
(expiration_date >> 11) & 0x1F);
if ((video_params >> 22) & 1)
av_log(s, AV_LOG_WARNING, "VBI data not yet supported\n");
if ((lxf->channels = 1 << (disk_params >> 4 & 3) + 1)) {
if (!(st = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->sample_rate = LXF_SAMPLERATE;
st->codec->channels = lxf->channels;
avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
}
avio_skip(s->pb, lxf->extended_size);
return 0;
}
static int lxf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
LXFDemuxContext *lxf = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *ast = NULL;
uint32_t stream;
int ret, ret2;
if ((ret = get_packet_header(s)) < 0)
return ret;
stream = lxf->packet_type;
if (stream > 1) {
av_log(s, AV_LOG_WARNING, "got packet with illegal stream index %u\n", stream);
return AVERROR(EAGAIN);
}
if (stream == 1 && !(ast = s->streams[1])) {
av_log(s, AV_LOG_ERROR, "got audio packet without having an audio stream\n");
return AVERROR_INVALIDDATA;
}
if ((ret2 = av_new_packet(pkt, ret)) < 0)
return ret2;
if ((ret2 = avio_read(pb, pkt->data, ret)) != ret) {
av_free_packet(pkt);
return ret2 < 0 ? ret2 : AVERROR_EOF;
}
pkt->stream_index = stream;
if (!ast) {
//picture type (0 = closed I, 1 = open I, 2 = P, 3 = B)
if (((lxf->video_format >> 22) & 0x3) < 2)
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->dts = lxf->frame_number++;
}
return ret;
}
AVInputFormat ff_lxf_demuxer = {
.name = "lxf",
.long_name = NULL_IF_CONFIG_SMALL("VR native stream (LXF)"),
.priv_data_size = sizeof(LXFDemuxContext),
.read_probe = lxf_probe,
.read_header = lxf_read_header,
.read_packet = lxf_read_packet,
.codec_tag = (const AVCodecTag* const []){lxf_tags, 0},
};
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