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/*
* GXF demuxer.
* Copyright (c) 2006 Reimar Doeffinger.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
typedef enum {
PKT_MAP = 0xbc,
PKT_MEDIA = 0xbf,
PKT_EOS = 0xfb,
PKT_FLT = 0xfc,
PKT_UMF = 0xfd
} pkt_type_t;
/**
* \brief parses a packet header, extracting type and length
* \param pb ByteIOContext to read header from
* \param type detected packet type is stored here
* \param length detected packet length, excluding header is stored here
* \return 0 if header not found or contains invalid data, 1 otherwise
*/
static int parse_packet_header(ByteIOContext *pb, pkt_type_t *type, int *length) {
if (get_be32(pb))
return 0;
if (get_byte(pb) != 1)
return 0;
*type = get_byte(pb);
*length = get_be32(pb);
if ((*length >> 24) || *length < 16)
return 0;
*length -= 16;
if (get_be32(pb))
return 0;
if (get_byte(pb) != 0xe1)
return 0;
if (get_byte(pb) != 0xe2)
return 0;
return 1;
}
/**
* \brief check if file starts with a PKT_MAP header
*/
static int gxf_probe(AVProbeData *p) {
static const uint8_t startcode[] = {0, 0, 0, 0, 1, 0xbc}; // start with map packet
static const uint8_t endcode[] = {0, 0, 0, 0, 0xe1, 0xe2};
if (p->buf_size < 16)
return 0;
if (!memcmp(p->buf, startcode, sizeof(startcode)) &&
!memcmp(&p->buf[16 - sizeof(endcode)], endcode, sizeof(endcode)))
return AVPROBE_SCORE_MAX;
return 0;
}
/**
* \brief gets the stream index for the track with the specified id, creates new
* stream if not found
* \param stream id of stream to find / add
* \param format stream format identifier
*/
static int get_sindex(AVFormatContext *s, int id, int format) {
int i;
AVStream *st = NULL;
for (i = 0; i < s->nb_streams; i++) {
if (s->streams[i]->id == id)
return i;
}
st = av_new_stream(s, id);
switch (format) {
case 3:
case 4:
st->codec->codec_type = CODEC_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_MJPEG;
st->codec->codec_tag = MKTAG('M', 'J', 'P', 'G');
break;
case 13:
case 15:
st->codec->codec_type = CODEC_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_DVVIDEO;
st->codec->codec_tag = MKTAG('d', 'v', 'c', ' ');
break;
case 14:
case 16:
st->codec->codec_type = CODEC_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_DVVIDEO;
st->codec->codec_tag = MKTAG('d', 'v', 'c', 'p');
break;
case 11:
case 12:
case 20:
st->codec->codec_type = CODEC_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
st->codec->codec_tag = MKTAG('M', 'P', 'G', '2');
break;
case 22:
case 23:
st->codec->codec_type = CODEC_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_MPEG1VIDEO;
st->codec->codec_tag = MKTAG('M', 'P', 'G', '1');
break;
case 9:
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_PCM_S24LE;
st->codec->codec_tag = 0x1;
st->codec->channels = 1;
st->codec->sample_rate = 48000;
st->codec->bit_rate = 3 * 1 * 48000 * 8;
st->codec->block_align = 3 * 1;
st->codec->bits_per_sample = 24;
break;
case 10:
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_PCM_S16LE;
st->codec->codec_tag = 0x1;
st->codec->channels = 1;
st->codec->sample_rate = 48000;
st->codec->bit_rate = 2 * 1 * 48000 * 8;
st->codec->block_align = 2 * 1;
st->codec->bits_per_sample = 16;
break;
case 17:
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_AC3;
st->codec->codec_tag = 0x2000;
st->codec->channels = 2;
st->codec->sample_rate = 48000;
break;
default:
st->codec->codec_type = CODEC_TYPE_UNKNOWN;
st->codec->codec_id = CODEC_ID_NONE;
break;
}
return s->nb_streams - 1;
}
static int gxf_header(AVFormatContext *s, AVFormatParameters *ap) {
ByteIOContext *pb = &s->pb;
pkt_type_t pkt_type;
int map_len;
int len;
if (!parse_packet_header(pb, &pkt_type, &map_len) || pkt_type != PKT_MAP) {
av_log(s, AV_LOG_ERROR, "GXF: map packet not found\n");
return 0;
}
map_len -= 2;
if (get_byte(pb) != 0x0e0 || get_byte(pb) != 0xff) {
av_log(s, AV_LOG_ERROR, "GXF: unknown version or invalid map preamble\n");
return 0;
}
map_len -= 2;
len = get_be16(pb); // length of material data section
if (len > map_len) {
av_log(s, AV_LOG_ERROR, "GXF: material data longer than map data\n");
return 0;
}
map_len -= len;
url_fskip(pb, len);
map_len -= 2;
len = get_be16(pb); // length of track description
if (len > map_len) {
av_log(s, AV_LOG_ERROR, "GXF: track description longer than map data\n");
return 0;
}
map_len -= len;
while (len > 0) {
int track_type, track_id, track_len;
len -= 4;
track_type = get_byte(pb);
track_id = get_byte(pb);
track_len = get_be16(pb);
len -= track_len;
url_fskip(pb, track_len);
if (!(track_type & 0x80)) {
av_log(s, AV_LOG_ERROR, "GXF: invalid track type %x\n", track_type);
continue;
}
track_type &= 0x7f;
if ((track_id & 0xc0) != 0xc0) {
av_log(s, AV_LOG_ERROR, "GXF: invalid track id %x\n", track_id);
continue;
}
track_id &= 0x3f;
get_sindex(s, track_id, track_type);
}
if (len < 0)
av_log(s, AV_LOG_ERROR, "GXF: invalid track description length specified\n");
if (map_len)
url_fskip(pb, map_len);
return 0;
}
static int gxf_packet(AVFormatContext *s, AVPacket *pkt) {
ByteIOContext *pb = &s->pb;
pkt_type_t pkt_type;
int pkt_len;
while (!url_feof(pb)) {
int track_type, track_id, ret;
if (!parse_packet_header(pb, &pkt_type, &pkt_len)) {
if (!url_feof(pb))
av_log(s, AV_LOG_ERROR, "GXF: sync lost\n");
return -1;
}
if (pkt_type != PKT_MEDIA) {
url_fskip(pb, pkt_len);
continue;
}
if (pkt_len < 16) {
av_log(s, AV_LOG_ERROR, "GXF: invalid media packet length\n");
continue;
}
pkt_len -= 16;
track_type = get_byte(pb);
track_id = get_byte(pb);
get_be32(pb); // field number
get_be32(pb); // field information
get_be32(pb); // "timeline" field number
get_byte(pb); // flags
get_byte(pb); // reserved
// NOTE: there is also data length information in the
// field information, it might be better to take this int account
// as well.
ret = av_get_packet(pb, pkt, pkt_len);
pkt->stream_index = get_sindex(s, track_id, track_type);
return ret;
}
return AVERROR_IO;
}
AVInputFormat gxf_demuxer = {
"gxf",
"GXF format",
0,
gxf_probe,
gxf_header,
gxf_packet,
NULL,
NULL,
};
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