blob: 16381db9054f4062b5486e11d0bb17914f33adc7
1 | /* |
2 | * TechnoTrend PVA (.pva) demuxer |
3 | * Copyright (c) 2007, 2008 Ivo van Poorten |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
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. |
11 | * |
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. |
16 | * |
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 |
20 | */ |
21 | |
22 | #include "avformat.h" |
23 | #include "internal.h" |
24 | #include "mpeg.h" |
25 | |
26 | #define PVA_MAX_PAYLOAD_LENGTH 0x17f8 |
27 | #define PVA_VIDEO_PAYLOAD 0x01 |
28 | #define PVA_AUDIO_PAYLOAD 0x02 |
29 | #define PVA_MAGIC (('A' << 8) + 'V') |
30 | |
31 | typedef struct PVAContext { |
32 | int continue_pes; |
33 | } PVAContext; |
34 | |
35 | static int pva_check(const uint8_t *p) { |
36 | int length = AV_RB16(p + 6); |
37 | if (AV_RB16(p) != PVA_MAGIC || !p[2] || p[2] > 2 || p[4] != 0x55 || |
38 | (p[5] & 0xe0) || length > PVA_MAX_PAYLOAD_LENGTH) |
39 | return -1; |
40 | return length + 8; |
41 | } |
42 | |
43 | static int pva_probe(AVProbeData * pd) { |
44 | const unsigned char *buf = pd->buf; |
45 | int len = pva_check(buf); |
46 | |
47 | if (len < 0) |
48 | return 0; |
49 | |
50 | if (pd->buf_size >= len + 8 && |
51 | pva_check(buf + len) >= 0) |
52 | return AVPROBE_SCORE_EXTENSION; |
53 | |
54 | return AVPROBE_SCORE_MAX / 4; |
55 | } |
56 | |
57 | static int pva_read_header(AVFormatContext *s) { |
58 | AVStream *st; |
59 | |
60 | if (!(st = avformat_new_stream(s, NULL))) |
61 | return AVERROR(ENOMEM); |
62 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
63 | st->codecpar->codec_id = AV_CODEC_ID_MPEG2VIDEO; |
64 | st->need_parsing = AVSTREAM_PARSE_FULL; |
65 | avpriv_set_pts_info(st, 32, 1, 90000); |
66 | av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME); |
67 | |
68 | if (!(st = avformat_new_stream(s, NULL))) |
69 | return AVERROR(ENOMEM); |
70 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
71 | st->codecpar->codec_id = AV_CODEC_ID_MP2; |
72 | st->need_parsing = AVSTREAM_PARSE_FULL; |
73 | avpriv_set_pts_info(st, 33, 1, 90000); |
74 | av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME); |
75 | |
76 | /* the parameters will be extracted from the compressed bitstream */ |
77 | return 0; |
78 | } |
79 | |
80 | #define pva_log if (read_packet) av_log |
81 | |
82 | static int read_part_of_packet(AVFormatContext *s, int64_t *pts, |
83 | int *len, int *strid, int read_packet) { |
84 | AVIOContext *pb = s->pb; |
85 | PVAContext *pvactx = s->priv_data; |
86 | int syncword, streamid, reserved, flags, length, pts_flag; |
87 | int64_t pva_pts = AV_NOPTS_VALUE, startpos; |
88 | int ret; |
89 | |
90 | recover: |
91 | startpos = avio_tell(pb); |
92 | |
93 | syncword = avio_rb16(pb); |
94 | streamid = avio_r8(pb); |
95 | avio_r8(pb); /* counter not used */ |
96 | reserved = avio_r8(pb); |
97 | flags = avio_r8(pb); |
98 | length = avio_rb16(pb); |
99 | |
100 | pts_flag = flags & 0x10; |
101 | |
102 | if (syncword != PVA_MAGIC) { |
103 | pva_log(s, AV_LOG_ERROR, "invalid syncword\n"); |
104 | return AVERROR(EIO); |
105 | } |
106 | if (streamid != PVA_VIDEO_PAYLOAD && streamid != PVA_AUDIO_PAYLOAD) { |
107 | pva_log(s, AV_LOG_ERROR, "invalid streamid\n"); |
108 | return AVERROR(EIO); |
109 | } |
110 | if (reserved != 0x55) { |
111 | pva_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n"); |
112 | } |
113 | if (length > PVA_MAX_PAYLOAD_LENGTH) { |
114 | pva_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length); |
115 | return AVERROR(EIO); |
116 | } |
117 | |
118 | if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) { |
119 | pva_pts = avio_rb32(pb); |
120 | length -= 4; |
121 | } else if (streamid == PVA_AUDIO_PAYLOAD) { |
122 | /* PVA Audio Packets either start with a signaled PES packet or |
123 | * are a continuation of the previous PES packet. New PES packets |
124 | * always start at the beginning of a PVA Packet, never somewhere in |
125 | * the middle. */ |
126 | if (!pvactx->continue_pes) { |
127 | int pes_signal, pes_header_data_length, pes_packet_length, |
128 | pes_flags; |
129 | unsigned char pes_header_data[256]; |
130 | |
131 | pes_signal = avio_rb24(pb); |
132 | avio_r8(pb); |
133 | pes_packet_length = avio_rb16(pb); |
134 | pes_flags = avio_rb16(pb); |
135 | pes_header_data_length = avio_r8(pb); |
136 | |
137 | if (pes_signal != 1 || pes_header_data_length == 0) { |
138 | pva_log(s, AV_LOG_WARNING, "expected non empty signaled PES packet, " |
139 | "trying to recover\n"); |
140 | avio_skip(pb, length - 9); |
141 | if (!read_packet) |
142 | return AVERROR(EIO); |
143 | goto recover; |
144 | } |
145 | |
146 | ret = avio_read(pb, pes_header_data, pes_header_data_length); |
147 | if (ret != pes_header_data_length) |
148 | return ret < 0 ? ret : AVERROR_INVALIDDATA; |
149 | length -= 9 + pes_header_data_length; |
150 | |
151 | pes_packet_length -= 3 + pes_header_data_length; |
152 | |
153 | pvactx->continue_pes = pes_packet_length; |
154 | |
155 | if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20) { |
156 | if (pes_header_data_length < 5) { |
157 | pva_log(s, AV_LOG_ERROR, "header too short\n"); |
158 | avio_skip(pb, length); |
159 | return AVERROR_INVALIDDATA; |
160 | } |
161 | pva_pts = ff_parse_pes_pts(pes_header_data); |
162 | } |
163 | } |
164 | |
165 | pvactx->continue_pes -= length; |
166 | |
167 | if (pvactx->continue_pes < 0) { |
168 | pva_log(s, AV_LOG_WARNING, "audio data corruption\n"); |
169 | pvactx->continue_pes = 0; |
170 | } |
171 | } |
172 | |
173 | if (pva_pts != AV_NOPTS_VALUE) |
174 | av_add_index_entry(s->streams[streamid-1], startpos, pva_pts, 0, 0, AVINDEX_KEYFRAME); |
175 | |
176 | *pts = pva_pts; |
177 | *len = length; |
178 | *strid = streamid; |
179 | return 0; |
180 | } |
181 | |
182 | static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) { |
183 | AVIOContext *pb = s->pb; |
184 | int64_t pva_pts; |
185 | int ret, length, streamid; |
186 | |
187 | if (read_part_of_packet(s, &pva_pts, &length, &streamid, 1) < 0 || |
188 | (ret = av_get_packet(pb, pkt, length)) <= 0) |
189 | return AVERROR(EIO); |
190 | |
191 | pkt->stream_index = streamid - 1; |
192 | pkt->pts = pva_pts; |
193 | |
194 | return ret; |
195 | } |
196 | |
197 | static int64_t pva_read_timestamp(struct AVFormatContext *s, int stream_index, |
198 | int64_t *pos, int64_t pos_limit) { |
199 | AVIOContext *pb = s->pb; |
200 | PVAContext *pvactx = s->priv_data; |
201 | int length, streamid; |
202 | int64_t res = AV_NOPTS_VALUE; |
203 | |
204 | pos_limit = FFMIN(*pos+PVA_MAX_PAYLOAD_LENGTH*8, (uint64_t)*pos+pos_limit); |
205 | |
206 | while (*pos < pos_limit) { |
207 | res = AV_NOPTS_VALUE; |
208 | avio_seek(pb, *pos, SEEK_SET); |
209 | |
210 | pvactx->continue_pes = 0; |
211 | if (read_part_of_packet(s, &res, &length, &streamid, 0)) { |
212 | (*pos)++; |
213 | continue; |
214 | } |
215 | if (streamid - 1 != stream_index || res == AV_NOPTS_VALUE) { |
216 | *pos = avio_tell(pb) + length; |
217 | continue; |
218 | } |
219 | break; |
220 | } |
221 | |
222 | pvactx->continue_pes = 0; |
223 | return res; |
224 | } |
225 | |
226 | AVInputFormat ff_pva_demuxer = { |
227 | .name = "pva", |
228 | .long_name = NULL_IF_CONFIG_SMALL("TechnoTrend PVA"), |
229 | .priv_data_size = sizeof(PVAContext), |
230 | .read_probe = pva_probe, |
231 | .read_header = pva_read_header, |
232 | .read_packet = pva_read_packet, |
233 | .read_timestamp = pva_read_timestamp, |
234 | }; |
235 |