2 * TechnoTrend PVA (.pva) demuxer
3 * Copyright (c) 2007, 2008 Ivo van Poorten
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
25 #define PVA_MAX_PAYLOAD_LENGTH 0x17f8
26 #define PVA_VIDEO_PAYLOAD 0x01
27 #define PVA_AUDIO_PAYLOAD 0x02
28 #define PVA_MAGIC (('A' << 8) + 'V')
34 static int pva_check(uint8_t *p) {
35 int length = AV_RB16(p + 6);
36 if (AV_RB16(p) != PVA_MAGIC || !p[2] || p[2] > 2 || p[4] != 0x55 ||
37 (p[5] & 0xe0) || length > PVA_MAX_PAYLOAD_LENGTH)
42 static int pva_probe(AVProbeData * pd) {
43 unsigned char *buf = pd->buf;
44 int len = pva_check(buf);
49 if (pd->buf_size >= len + 8 &&
50 pva_check(buf + len) >= 0)
51 return AVPROBE_SCORE_MAX / 2;
53 return AVPROBE_SCORE_MAX / 4;
56 static int pva_read_header(AVFormatContext *s, AVFormatParameters *ap) {
59 if (!(st = av_new_stream(s, 0)))
60 return AVERROR(ENOMEM);
61 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
62 st->codec->codec_id = CODEC_ID_MPEG2VIDEO;
63 st->need_parsing = AVSTREAM_PARSE_FULL;
64 av_set_pts_info(st, 32, 1, 90000);
65 av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME);
67 if (!(st = av_new_stream(s, 1)))
68 return AVERROR(ENOMEM);
69 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
70 st->codec->codec_id = CODEC_ID_MP2;
71 st->need_parsing = AVSTREAM_PARSE_FULL;
72 av_set_pts_info(st, 33, 1, 90000);
73 av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME);
75 /* the parameters will be extracted from the compressed bitstream */
79 #define pva_log if (read_packet) av_log
81 static int read_part_of_packet(AVFormatContext *s, int64_t *pts,
82 int *len, int *strid, int read_packet) {
83 AVIOContext *pb = s->pb;
84 PVAContext *pvactx = s->priv_data;
85 int syncword, streamid, reserved, flags, length, pts_flag;
86 int64_t pva_pts = AV_NOPTS_VALUE, startpos;
89 startpos = avio_tell(pb);
91 syncword = avio_rb16(pb);
92 streamid = avio_r8(pb);
93 avio_r8(pb); /* counter not used */
94 reserved = avio_r8(pb);
96 length = avio_rb16(pb);
98 pts_flag = flags & 0x10;
100 if (syncword != PVA_MAGIC) {
101 pva_log(s, AV_LOG_ERROR, "invalid syncword\n");
104 if (streamid != PVA_VIDEO_PAYLOAD && streamid != PVA_AUDIO_PAYLOAD) {
105 pva_log(s, AV_LOG_ERROR, "invalid streamid\n");
108 if (reserved != 0x55) {
109 pva_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n");
111 if (length > PVA_MAX_PAYLOAD_LENGTH) {
112 pva_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length);
116 if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) {
117 pva_pts = avio_rb32(pb);
119 } else if (streamid == PVA_AUDIO_PAYLOAD) {
120 /* PVA Audio Packets either start with a signaled PES packet or
121 * are a continuation of the previous PES packet. New PES packets
122 * always start at the beginning of a PVA Packet, never somewhere in
124 if (!pvactx->continue_pes) {
125 int pes_signal, pes_header_data_length, pes_packet_length,
127 unsigned char pes_header_data[256];
129 pes_signal = avio_rb24(pb);
131 pes_packet_length = avio_rb16(pb);
132 pes_flags = avio_rb16(pb);
133 pes_header_data_length = avio_r8(pb);
135 if (pes_signal != 1) {
136 pva_log(s, AV_LOG_WARNING, "expected signaled PES packet, "
137 "trying to recover\n");
138 avio_skip(pb, length - 9);
144 avio_read(pb, pes_header_data, pes_header_data_length);
145 length -= 9 + pes_header_data_length;
147 pes_packet_length -= 3 + pes_header_data_length;
149 pvactx->continue_pes = pes_packet_length;
151 if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20)
152 pva_pts = ff_parse_pes_pts(pes_header_data);
155 pvactx->continue_pes -= length;
157 if (pvactx->continue_pes < 0) {
158 pva_log(s, AV_LOG_WARNING, "audio data corruption\n");
159 pvactx->continue_pes = 0;
163 if (pva_pts != AV_NOPTS_VALUE)
164 av_add_index_entry(s->streams[streamid-1], startpos, pva_pts, 0, 0, AVINDEX_KEYFRAME);
172 static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) {
173 AVIOContext *pb = s->pb;
175 int ret, length, streamid;
177 if (read_part_of_packet(s, &pva_pts, &length, &streamid, 1) < 0 ||
178 (ret = av_get_packet(pb, pkt, length)) <= 0)
181 pkt->stream_index = streamid - 1;
187 static int64_t pva_read_timestamp(struct AVFormatContext *s, int stream_index,
188 int64_t *pos, int64_t pos_limit) {
189 AVIOContext *pb = s->pb;
190 PVAContext *pvactx = s->priv_data;
191 int length, streamid;
192 int64_t res = AV_NOPTS_VALUE;
194 pos_limit = FFMIN(*pos+PVA_MAX_PAYLOAD_LENGTH*8, (uint64_t)*pos+pos_limit);
196 while (*pos < pos_limit) {
197 res = AV_NOPTS_VALUE;
198 avio_seek(pb, *pos, SEEK_SET);
200 pvactx->continue_pes = 0;
201 if (read_part_of_packet(s, &res, &length, &streamid, 0)) {
205 if (streamid - 1 != stream_index || res == AV_NOPTS_VALUE) {
206 *pos = avio_tell(pb) + length;
212 pvactx->continue_pes = 0;
216 AVInputFormat ff_pva_demuxer = {
218 .long_name = NULL_IF_CONFIG_SMALL("TechnoTrend PVA file and stream format"),
219 .priv_data_size = sizeof(PVAContext),
220 .read_probe = pva_probe,
221 .read_header = pva_read_header,
222 .read_packet = pva_read_packet,
223 .read_timestamp = pva_read_timestamp