FFmpeg/libavformat/pva.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

212 lines
6.6 KiB
C

/*
* TechnoTrend PVA (.pva) demuxer
* Copyright (c) 2007, 2008 Ivo van Poorten
*
* 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 "avformat.h"
#include "mpeg.h"
#define PVA_MAX_PAYLOAD_LENGTH 0x17f8
#define PVA_VIDEO_PAYLOAD 0x01
#define PVA_AUDIO_PAYLOAD 0x02
#define PVA_MAGIC (('A' << 8) + 'V')
typedef struct {
int continue_pes;
} PVAContext;
static int pva_probe(AVProbeData * pd) {
unsigned char *buf = pd->buf;
if (AV_RB16(buf) == PVA_MAGIC && buf[2] && buf[2] < 3 && buf[4] == 0x55)
return AVPROBE_SCORE_MAX / 2;
return 0;
}
static int pva_read_header(AVFormatContext *s, AVFormatParameters *ap) {
AVStream *st;
if (!(st = av_new_stream(s, 0)))
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
st->need_parsing = AVSTREAM_PARSE_FULL;
av_set_pts_info(st, 32, 1, 90000);
av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME);
if (!(st = av_new_stream(s, 1)))
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_MP2;
st->need_parsing = AVSTREAM_PARSE_FULL;
av_set_pts_info(st, 33, 1, 90000);
av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME);
/* the parameters will be extracted from the compressed bitstream */
return 0;
}
#define pva_log if (read_packet) av_log
static int read_part_of_packet(AVFormatContext *s, int64_t *pts,
int *len, int *strid, int read_packet) {
ByteIOContext *pb = s->pb;
PVAContext *pvactx = s->priv_data;
int syncword, streamid, reserved, flags, length, pts_flag;
int64_t pva_pts = AV_NOPTS_VALUE, startpos;
recover:
startpos = url_ftell(pb);
syncword = get_be16(pb);
streamid = get_byte(pb);
get_byte(pb); /* counter not used */
reserved = get_byte(pb);
flags = get_byte(pb);
length = get_be16(pb);
pts_flag = flags & 0x10;
if (syncword != PVA_MAGIC) {
pva_log(s, AV_LOG_ERROR, "invalid syncword\n");
return AVERROR(EIO);
}
if (streamid != PVA_VIDEO_PAYLOAD && streamid != PVA_AUDIO_PAYLOAD) {
pva_log(s, AV_LOG_ERROR, "invalid streamid\n");
return AVERROR(EIO);
}
if (reserved != 0x55) {
pva_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n");
}
if (length > PVA_MAX_PAYLOAD_LENGTH) {
pva_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length);
return AVERROR(EIO);
}
if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) {
pva_pts = get_be32(pb);
length -= 4;
} else if (streamid == PVA_AUDIO_PAYLOAD) {
/* PVA Audio Packets either start with a signaled PES packet or
* are a continuation of the previous PES packet. New PES packets
* always start at the beginning of a PVA Packet, never somewhere in
* the middle. */
if (!pvactx->continue_pes) {
int pes_signal, pes_header_data_length, pes_packet_length,
pes_flags;
unsigned char pes_header_data[256];
pes_signal = get_be24(pb);
get_byte(pb);
pes_packet_length = get_be16(pb);
pes_flags = get_be16(pb);
pes_header_data_length = get_byte(pb);
if (pes_signal != 1) {
pva_log(s, AV_LOG_WARNING, "expected signaled PES packet, "
"trying to recover\n");
url_fskip(pb, length - 9);
if (!read_packet)
return AVERROR(EIO);
goto recover;
}
get_buffer(pb, pes_header_data, pes_header_data_length);
length -= 9 + pes_header_data_length;
pes_packet_length -= 3 + pes_header_data_length;
pvactx->continue_pes = pes_packet_length;
if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20)
pva_pts = ff_parse_pes_pts(pes_header_data);
}
pvactx->continue_pes -= length;
if (pvactx->continue_pes < 0) {
pva_log(s, AV_LOG_WARNING, "audio data corruption\n");
pvactx->continue_pes = 0;
}
}
if (pva_pts != AV_NOPTS_VALUE)
av_add_index_entry(s->streams[streamid-1], startpos, pva_pts, 0, 0, AVINDEX_KEYFRAME);
*pts = pva_pts;
*len = length;
*strid = streamid;
return 0;
}
static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) {
ByteIOContext *pb = s->pb;
int64_t pva_pts;
int ret, length, streamid;
if (read_part_of_packet(s, &pva_pts, &length, &streamid, 1) < 0 ||
(ret = av_get_packet(pb, pkt, length)) <= 0)
return AVERROR(EIO);
pkt->stream_index = streamid - 1;
pkt->pts = pva_pts;
return ret;
}
static int64_t pva_read_timestamp(struct AVFormatContext *s, int stream_index,
int64_t *pos, int64_t pos_limit) {
ByteIOContext *pb = s->pb;
PVAContext *pvactx = s->priv_data;
int length, streamid;
int64_t res = AV_NOPTS_VALUE;
pos_limit = FFMIN(*pos+PVA_MAX_PAYLOAD_LENGTH*8, (uint64_t)*pos+pos_limit);
while (*pos < pos_limit) {
res = AV_NOPTS_VALUE;
url_fseek(pb, *pos, SEEK_SET);
pvactx->continue_pes = 0;
if (read_part_of_packet(s, &res, &length, &streamid, 0)) {
(*pos)++;
continue;
}
if (streamid - 1 != stream_index || res == AV_NOPTS_VALUE) {
*pos = url_ftell(pb) + length;
continue;
}
break;
}
pvactx->continue_pes = 0;
return res;
}
AVInputFormat pva_demuxer = {
"pva",
NULL_IF_CONFIG_SMALL("TechnoTrend PVA file and stream format"),
sizeof(PVAContext),
pva_probe,
pva_read_header,
pva_read_packet,
.read_timestamp = pva_read_timestamp
};