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Rev | Author | Line No. | Line |
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6147 | serge | 1 | /* |
2 | * TechnoTrend PVA (.pva) demuxer |
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3 | * Copyright (c) 2007, 2008 Ivo van Poorten |
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4 | * |
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5 | * This file is part of FFmpeg. |
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6 | * |
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7 | * FFmpeg is free software; you can redistribute it and/or |
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8 | * modify it under the terms of the GNU Lesser General Public |
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9 | * License as published by the Free Software Foundation; either |
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10 | * version 2.1 of the License, or (at your option) any later version. |
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11 | * |
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12 | * FFmpeg is distributed in the hope that it will be useful, |
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13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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15 | * Lesser General Public License for more details. |
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16 | * |
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17 | * You should have received a copy of the GNU Lesser General Public |
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18 | * License along with FFmpeg; if not, write to the Free Software |
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19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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20 | */ |
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21 | |||
22 | #include "avformat.h" |
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23 | #include "internal.h" |
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24 | #include "mpeg.h" |
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25 | |||
26 | #define PVA_MAX_PAYLOAD_LENGTH 0x17f8 |
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27 | #define PVA_VIDEO_PAYLOAD 0x01 |
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28 | #define PVA_AUDIO_PAYLOAD 0x02 |
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29 | #define PVA_MAGIC (('A' << 8) + 'V') |
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30 | |||
31 | typedef struct PVAContext { |
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32 | int continue_pes; |
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33 | } PVAContext; |
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34 | |||
35 | static int pva_check(const uint8_t *p) { |
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36 | int length = AV_RB16(p + 6); |
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37 | if (AV_RB16(p) != PVA_MAGIC || !p[2] || p[2] > 2 || p[4] != 0x55 || |
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38 | (p[5] & 0xe0) || length > PVA_MAX_PAYLOAD_LENGTH) |
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39 | return -1; |
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40 | return length + 8; |
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41 | } |
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42 | |||
43 | static int pva_probe(AVProbeData * pd) { |
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44 | const unsigned char *buf = pd->buf; |
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45 | int len = pva_check(buf); |
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46 | |||
47 | if (len < 0) |
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48 | return 0; |
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49 | |||
50 | if (pd->buf_size >= len + 8 && |
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51 | pva_check(buf + len) >= 0) |
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52 | return AVPROBE_SCORE_EXTENSION; |
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53 | |||
54 | return AVPROBE_SCORE_MAX / 4; |
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55 | } |
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56 | |||
57 | static int pva_read_header(AVFormatContext *s) { |
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58 | AVStream *st; |
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59 | |||
60 | if (!(st = avformat_new_stream(s, NULL))) |
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61 | return AVERROR(ENOMEM); |
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62 | st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
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63 | st->codec->codec_id = AV_CODEC_ID_MPEG2VIDEO; |
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64 | st->need_parsing = AVSTREAM_PARSE_FULL; |
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65 | avpriv_set_pts_info(st, 32, 1, 90000); |
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66 | av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME); |
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67 | |||
68 | if (!(st = avformat_new_stream(s, NULL))) |
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69 | return AVERROR(ENOMEM); |
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70 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
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71 | st->codec->codec_id = AV_CODEC_ID_MP2; |
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72 | st->need_parsing = AVSTREAM_PARSE_FULL; |
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73 | avpriv_set_pts_info(st, 33, 1, 90000); |
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74 | av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME); |
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75 | |||
76 | /* the parameters will be extracted from the compressed bitstream */ |
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77 | return 0; |
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78 | } |
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79 | |||
80 | #define pva_log if (read_packet) av_log |
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81 | |||
82 | static int read_part_of_packet(AVFormatContext *s, int64_t *pts, |
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83 | int *len, int *strid, int read_packet) { |
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84 | AVIOContext *pb = s->pb; |
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85 | PVAContext *pvactx = s->priv_data; |
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86 | int syncword, streamid, reserved, flags, length, pts_flag; |
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87 | int64_t pva_pts = AV_NOPTS_VALUE, startpos; |
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88 | int ret; |
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89 | |||
90 | recover: |
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91 | startpos = avio_tell(pb); |
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92 | |||
93 | syncword = avio_rb16(pb); |
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94 | streamid = avio_r8(pb); |
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95 | avio_r8(pb); /* counter not used */ |
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96 | reserved = avio_r8(pb); |
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97 | flags = avio_r8(pb); |
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98 | length = avio_rb16(pb); |
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99 | |||
100 | pts_flag = flags & 0x10; |
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101 | |||
102 | if (syncword != PVA_MAGIC) { |
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103 | pva_log(s, AV_LOG_ERROR, "invalid syncword\n"); |
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104 | return AVERROR(EIO); |
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105 | } |
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106 | if (streamid != PVA_VIDEO_PAYLOAD && streamid != PVA_AUDIO_PAYLOAD) { |
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107 | pva_log(s, AV_LOG_ERROR, "invalid streamid\n"); |
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108 | return AVERROR(EIO); |
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109 | } |
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110 | if (reserved != 0x55) { |
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111 | pva_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n"); |
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112 | } |
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113 | if (length > PVA_MAX_PAYLOAD_LENGTH) { |
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114 | pva_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length); |
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115 | return AVERROR(EIO); |
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116 | } |
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117 | |||
118 | if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) { |
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119 | pva_pts = avio_rb32(pb); |
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120 | length -= 4; |
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121 | } else if (streamid == PVA_AUDIO_PAYLOAD) { |
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122 | /* PVA Audio Packets either start with a signaled PES packet or |
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123 | * are a continuation of the previous PES packet. New PES packets |
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124 | * always start at the beginning of a PVA Packet, never somewhere in |
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125 | * the middle. */ |
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126 | if (!pvactx->continue_pes) { |
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127 | int pes_signal, pes_header_data_length, pes_packet_length, |
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128 | pes_flags; |
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129 | unsigned char pes_header_data[256]; |
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130 | |||
131 | pes_signal = avio_rb24(pb); |
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132 | avio_r8(pb); |
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133 | pes_packet_length = avio_rb16(pb); |
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134 | pes_flags = avio_rb16(pb); |
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135 | pes_header_data_length = avio_r8(pb); |
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136 | |||
137 | if (pes_signal != 1 || pes_header_data_length == 0) { |
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138 | pva_log(s, AV_LOG_WARNING, "expected non empty signaled PES packet, " |
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139 | "trying to recover\n"); |
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140 | avio_skip(pb, length - 9); |
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141 | if (!read_packet) |
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142 | return AVERROR(EIO); |
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143 | goto recover; |
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144 | } |
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145 | |||
146 | ret = avio_read(pb, pes_header_data, pes_header_data_length); |
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147 | if (ret != pes_header_data_length) |
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148 | return ret < 0 ? ret : AVERROR_INVALIDDATA; |
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149 | length -= 9 + pes_header_data_length; |
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150 | |||
151 | pes_packet_length -= 3 + pes_header_data_length; |
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152 | |||
153 | pvactx->continue_pes = pes_packet_length; |
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154 | |||
155 | if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20) { |
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156 | if (pes_header_data_length < 5) { |
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157 | pva_log(s, AV_LOG_ERROR, "header too short\n"); |
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158 | avio_skip(pb, length); |
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159 | return AVERROR_INVALIDDATA; |
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160 | } |
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161 | pva_pts = ff_parse_pes_pts(pes_header_data); |
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162 | } |
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163 | } |
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164 | |||
165 | pvactx->continue_pes -= length; |
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166 | |||
167 | if (pvactx->continue_pes < 0) { |
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168 | pva_log(s, AV_LOG_WARNING, "audio data corruption\n"); |
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169 | pvactx->continue_pes = 0; |
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170 | } |
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171 | } |
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172 | |||
173 | if (pva_pts != AV_NOPTS_VALUE) |
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174 | av_add_index_entry(s->streams[streamid-1], startpos, pva_pts, 0, 0, AVINDEX_KEYFRAME); |
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175 | |||
176 | *pts = pva_pts; |
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177 | *len = length; |
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178 | *strid = streamid; |
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179 | return 0; |
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180 | } |
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181 | |||
182 | static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) { |
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183 | AVIOContext *pb = s->pb; |
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184 | int64_t pva_pts; |
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185 | int ret, length, streamid; |
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186 | |||
187 | if (read_part_of_packet(s, &pva_pts, &length, &streamid, 1) < 0 || |
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188 | (ret = av_get_packet(pb, pkt, length)) <= 0) |
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189 | return AVERROR(EIO); |
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190 | |||
191 | pkt->stream_index = streamid - 1; |
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192 | pkt->pts = pva_pts; |
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193 | |||
194 | return ret; |
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195 | } |
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196 | |||
197 | static int64_t pva_read_timestamp(struct AVFormatContext *s, int stream_index, |
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198 | int64_t *pos, int64_t pos_limit) { |
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199 | AVIOContext *pb = s->pb; |
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200 | PVAContext *pvactx = s->priv_data; |
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201 | int length, streamid; |
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202 | int64_t res = AV_NOPTS_VALUE; |
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203 | |||
204 | pos_limit = FFMIN(*pos+PVA_MAX_PAYLOAD_LENGTH*8, (uint64_t)*pos+pos_limit); |
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205 | |||
206 | while (*pos < pos_limit) { |
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207 | res = AV_NOPTS_VALUE; |
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208 | avio_seek(pb, *pos, SEEK_SET); |
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209 | |||
210 | pvactx->continue_pes = 0; |
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211 | if (read_part_of_packet(s, &res, &length, &streamid, 0)) { |
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212 | (*pos)++; |
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213 | continue; |
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214 | } |
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215 | if (streamid - 1 != stream_index || res == AV_NOPTS_VALUE) { |
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216 | *pos = avio_tell(pb) + length; |
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217 | continue; |
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218 | } |
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219 | break; |
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220 | } |
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221 | |||
222 | pvactx->continue_pes = 0; |
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223 | return res; |
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224 | } |
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225 | |||
226 | AVInputFormat ff_pva_demuxer = { |
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227 | .name = "pva", |
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228 | .long_name = NULL_IF_CONFIG_SMALL("TechnoTrend PVA"), |
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229 | .priv_data_size = sizeof(PVAContext), |
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230 | .read_probe = pva_probe, |
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231 | .read_header = pva_read_header, |
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232 | .read_packet = pva_read_packet, |
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233 | .read_timestamp = pva_read_timestamp, |
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234 | };>=>>>>>>><> |