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< li class = "navelem" > < a class = "el" href = "../../dir_39dc0668bd5a501998f94e8b4e546c71.html" > media< / a > < / li > < li class = "navelem" > < a class = "el" href = "../../dir_5eb2e460866db0ed29e32d64402e5c22.html" > filters< / a > < / li > < / ul >
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< div class = "fragment" > < div class = "line" > < a name = "l00001" > < / a > < span class = "lineno" > 1< / span >   < span class = "comment" > // Copyright 2014 The Chromium Authors. All rights reserved.< / span > < / div >
< div class = "line" > < a name = "l00002" > < / a > < span class = "lineno" > 2< / span >   < span class = "comment" > // Use of this source code is governed by a BSD-style license that can be< / span > < / div >
< div class = "line" > < a name = "l00003" > < / a > < span class = "lineno" > 3< / span >   < span class = "comment" > // found in the LICENSE file.< / span > < / div >
< div class = "line" > < a name = "l00004" > < / a > < span class = "lineno" > 4< / span >   < / div >
< div class = "line" > < a name = "l00005" > < / a > < span class = "lineno" > 5< / span >   < span class = "preprocessor" > #include " packager/base/logging.h" < / span > < / div >
< div class = "line" > < a name = "l00006" > < / a > < span class = "lineno" > 6< / span >   < span class = "preprocessor" > #include " packager/media/filters/h264_bit_reader.h" < / span > < / div >
< div class = "line" > < a name = "l00007" > < / a > < span class = "lineno" > 7< / span >   < / div >
< div class = "line" > < a name = "l00008" > < / a > < span class = "lineno" > 8< / span >   < span class = "keyword" > namespace < / span > edash_packager {< / div >
< div class = "line" > < a name = "l00009" > < / a > < span class = "lineno" > 9< / span >   < span class = "keyword" > namespace < / span > media {< / div >
< div class = "line" > < a name = "l00010" > < / a > < span class = "lineno" > 10< / span >   < / div >
< div class = "line" > < a name = "l00011" > < / a > < span class = "lineno" > 11< / span >   H264BitReader::H264BitReader()< / div >
< div class = "line" > < a name = "l00012" > < / a > < span class = "lineno" > 12< / span >   : data_(NULL),< / div >
< div class = "line" > < a name = "l00013" > < / a > < span class = "lineno" > 13< / span >   bytes_left_(0),< / div >
< div class = "line" > < a name = "l00014" > < / a > < span class = "lineno" > 14< / span >   curr_byte_(0),< / div >
< div class = "line" > < a name = "l00015" > < / a > < span class = "lineno" > 15< / span >   num_remaining_bits_in_curr_byte_(0),< / div >
< div class = "line" > < a name = "l00016" > < / a > < span class = "lineno" > 16< / span >   prev_two_bytes_(0),< / div >
< div class = "line" > < a name = "l00017" > < / a > < span class = "lineno" > 17< / span >   emulation_prevention_bytes_(0) {}< / div >
< div class = "line" > < a name = "l00018" > < / a > < span class = "lineno" > 18< / span >   < / div >
< div class = "line" > < a name = "l00019" > < / a > < span class = "lineno" > 19< / span >   H264BitReader::~H264BitReader() {}< / div >
< div class = "line" > < a name = "l00020" > < / a > < span class = "lineno" > 20< / span >   < / div >
< div class = "line" > < a name = "l00021" > < / a > < span class = "lineno" > 21< / span >   < span class = "keywordtype" > bool< / span > H264BitReader::Initialize(< span class = "keyword" > const< / span > uint8_t* data, off_t size) {< / div >
< div class = "line" > < a name = "l00022" > < / a > < span class = "lineno" > 22< / span >   DCHECK(data);< / div >
< div class = "line" > < a name = "l00023" > < / a > < span class = "lineno" > 23< / span >   < / div >
< div class = "line" > < a name = "l00024" > < / a > < span class = "lineno" > 24< / span >   < span class = "keywordflow" > if< / span > (size < 1)< / div >
< div class = "line" > < a name = "l00025" > < / a > < span class = "lineno" > 25< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > false< / span > ;< / div >
< div class = "line" > < a name = "l00026" > < / a > < span class = "lineno" > 26< / span >   < / div >
< div class = "line" > < a name = "l00027" > < / a > < span class = "lineno" > 27< / span >   data_ = data;< / div >
< div class = "line" > < a name = "l00028" > < / a > < span class = "lineno" > 28< / span >   bytes_left_ = size;< / div >
< div class = "line" > < a name = "l00029" > < / a > < span class = "lineno" > 29< / span >   num_remaining_bits_in_curr_byte_ = 0;< / div >
< div class = "line" > < a name = "l00030" > < / a > < span class = "lineno" > 30< / span >   < span class = "comment" > // Initially set to 0xffff to accept all initial two-byte sequences.< / span > < / div >
< div class = "line" > < a name = "l00031" > < / a > < span class = "lineno" > 31< / span >   prev_two_bytes_ = 0xffff;< / div >
< div class = "line" > < a name = "l00032" > < / a > < span class = "lineno" > 32< / span >   emulation_prevention_bytes_ = 0;< / div >
< div class = "line" > < a name = "l00033" > < / a > < span class = "lineno" > 33< / span >   < / div >
< div class = "line" > < a name = "l00034" > < / a > < span class = "lineno" > 34< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > true< / span > ;< / div >
< div class = "line" > < a name = "l00035" > < / a > < span class = "lineno" > 35< / span >   }< / div >
< div class = "line" > < a name = "l00036" > < / a > < span class = "lineno" > 36< / span >   < / div >
< div class = "line" > < a name = "l00037" > < / a > < span class = "lineno" > 37< / span >   < span class = "keywordtype" > bool< / span > H264BitReader::UpdateCurrByte() {< / div >
< div class = "line" > < a name = "l00038" > < / a > < span class = "lineno" > 38< / span >   < span class = "keywordflow" > if< / span > (bytes_left_ < 1)< / div >
< div class = "line" > < a name = "l00039" > < / a > < span class = "lineno" > 39< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > false< / span > ;< / div >
< div class = "line" > < a name = "l00040" > < / a > < span class = "lineno" > 40< / span >   < / div >
< div class = "line" > < a name = "l00041" > < / a > < span class = "lineno" > 41< / span >   < span class = "comment" > // Emulation prevention three-byte detection.< / span > < / div >
< div class = "line" > < a name = "l00042" > < / a > < span class = "lineno" > 42< / span >   < span class = "comment" > // If a sequence of 0x000003 is found, skip (ignore) the last byte (0x03).< / span > < / div >
< div class = "line" > < a name = "l00043" > < / a > < span class = "lineno" > 43< / span >   < span class = "keywordflow" > if< / span > (*data_ == 0x03 & & (prev_two_bytes_ & 0xffff) == 0) {< / div >
< div class = "line" > < a name = "l00044" > < / a > < span class = "lineno" > 44< / span >   < span class = "comment" > // Detected 0x000003, skip last byte.< / span > < / div >
< div class = "line" > < a name = "l00045" > < / a > < span class = "lineno" > 45< / span >   ++data_;< / div >
< div class = "line" > < a name = "l00046" > < / a > < span class = "lineno" > 46< / span >   --bytes_left_;< / div >
< div class = "line" > < a name = "l00047" > < / a > < span class = "lineno" > 47< / span >   ++emulation_prevention_bytes_;< / div >
< div class = "line" > < a name = "l00048" > < / a > < span class = "lineno" > 48< / span >   < span class = "comment" > // Need another full three bytes before we can detect the sequence again.< / span > < / div >
< div class = "line" > < a name = "l00049" > < / a > < span class = "lineno" > 49< / span >   prev_two_bytes_ = 0xffff;< / div >
< div class = "line" > < a name = "l00050" > < / a > < span class = "lineno" > 50< / span >   < / div >
< div class = "line" > < a name = "l00051" > < / a > < span class = "lineno" > 51< / span >   < span class = "keywordflow" > if< / span > (bytes_left_ < 1)< / div >
< div class = "line" > < a name = "l00052" > < / a > < span class = "lineno" > 52< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > false< / span > ;< / div >
< div class = "line" > < a name = "l00053" > < / a > < span class = "lineno" > 53< / span >   }< / div >
< div class = "line" > < a name = "l00054" > < / a > < span class = "lineno" > 54< / span >   < / div >
< div class = "line" > < a name = "l00055" > < / a > < span class = "lineno" > 55< / span >   < span class = "comment" > // Load a new byte and advance pointers.< / span > < / div >
< div class = "line" > < a name = "l00056" > < / a > < span class = "lineno" > 56< / span >   curr_byte_ = *data_++ & 0xff;< / div >
< div class = "line" > < a name = "l00057" > < / a > < span class = "lineno" > 57< / span >   --bytes_left_;< / div >
< div class = "line" > < a name = "l00058" > < / a > < span class = "lineno" > 58< / span >   num_remaining_bits_in_curr_byte_ = 8;< / div >
< div class = "line" > < a name = "l00059" > < / a > < span class = "lineno" > 59< / span >   < / div >
< div class = "line" > < a name = "l00060" > < / a > < span class = "lineno" > 60< / span >   prev_two_bytes_ = (prev_two_bytes_ < < 8) | curr_byte_;< / div >
< div class = "line" > < a name = "l00061" > < / a > < span class = "lineno" > 61< / span >   < / div >
< div class = "line" > < a name = "l00062" > < / a > < span class = "lineno" > 62< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > true< / span > ;< / div >
< div class = "line" > < a name = "l00063" > < / a > < span class = "lineno" > 63< / span >   }< / div >
< div class = "line" > < a name = "l00064" > < / a > < span class = "lineno" > 64< / span >   < / div >
< div class = "line" > < a name = "l00065" > < / a > < span class = "lineno" > 65< / span >   < span class = "comment" > // Read |num_bits| (1 to 31 inclusive) from the stream and return them< / span > < / div >
< div class = "line" > < a name = "l00066" > < / a > < span class = "lineno" > 66< / span >   < span class = "comment" > // in |out|, with first bit in the stream as MSB in |out| at position< / span > < / div >
< div class = "line" > < a name = "l00067" > < / a > < span class = "lineno" > 67< / span >   < span class = "comment" > // (|num_bits| - 1).< / span > < / div >
< div class = "line" > < a name = "l00068" > < / a > < span class = "lineno" > 68< / span >   < span class = "keywordtype" > bool< / span > H264BitReader::ReadBits(< span class = "keywordtype" > int< / span > num_bits, < span class = "keywordtype" > int< / span > * out) {< / div >
< div class = "line" > < a name = "l00069" > < / a > < span class = "lineno" > 69< / span >   < span class = "keywordtype" > int< / span > bits_left = num_bits;< / div >
< div class = "line" > < a name = "l00070" > < / a > < span class = "lineno" > 70< / span >   *out = 0;< / div >
< div class = "line" > < a name = "l00071" > < / a > < span class = "lineno" > 71< / span >   DCHECK(num_bits < = 31);< / div >
< div class = "line" > < a name = "l00072" > < / a > < span class = "lineno" > 72< / span >   < / div >
< div class = "line" > < a name = "l00073" > < / a > < span class = "lineno" > 73< / span >   < span class = "keywordflow" > while< / span > (num_remaining_bits_in_curr_byte_ < bits_left) {< / div >
< div class = "line" > < a name = "l00074" > < / a > < span class = "lineno" > 74< / span >   < span class = "comment" > // Take all that' s left in current byte, shift to make space for the rest.< / span > < / div >
< div class = "line" > < a name = "l00075" > < / a > < span class = "lineno" > 75< / span >   *out |= (curr_byte_ < < (bits_left - num_remaining_bits_in_curr_byte_));< / div >
< div class = "line" > < a name = "l00076" > < / a > < span class = "lineno" > 76< / span >   bits_left -= num_remaining_bits_in_curr_byte_;< / div >
< div class = "line" > < a name = "l00077" > < / a > < span class = "lineno" > 77< / span >   < / div >
< div class = "line" > < a name = "l00078" > < / a > < span class = "lineno" > 78< / span >   < span class = "keywordflow" > if< / span > (!UpdateCurrByte())< / div >
< div class = "line" > < a name = "l00079" > < / a > < span class = "lineno" > 79< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > false< / span > ;< / div >
< div class = "line" > < a name = "l00080" > < / a > < span class = "lineno" > 80< / span >   }< / div >
< div class = "line" > < a name = "l00081" > < / a > < span class = "lineno" > 81< / span >   < / div >
< div class = "line" > < a name = "l00082" > < / a > < span class = "lineno" > 82< / span >   *out |= (curr_byte_ > > (num_remaining_bits_in_curr_byte_ - bits_left));< / div >
< div class = "line" > < a name = "l00083" > < / a > < span class = "lineno" > 83< / span >   *out & = ((1 < < num_bits) - 1);< / div >
< div class = "line" > < a name = "l00084" > < / a > < span class = "lineno" > 84< / span >   num_remaining_bits_in_curr_byte_ -= bits_left;< / div >
< div class = "line" > < a name = "l00085" > < / a > < span class = "lineno" > 85< / span >   < / div >
< div class = "line" > < a name = "l00086" > < / a > < span class = "lineno" > 86< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > true< / span > ;< / div >
< div class = "line" > < a name = "l00087" > < / a > < span class = "lineno" > 87< / span >   }< / div >
< div class = "line" > < a name = "l00088" > < / a > < span class = "lineno" > 88< / span >   < / div >
< div class = "line" > < a name = "l00089" > < / a > < span class = "lineno" > 89< / span >   off_t H264BitReader::NumBitsLeft() {< / div >
< div class = "line" > < a name = "l00090" > < / a > < span class = "lineno" > 90< / span >   < span class = "keywordflow" > return< / span > (num_remaining_bits_in_curr_byte_ + bytes_left_ * 8);< / div >
< div class = "line" > < a name = "l00091" > < / a > < span class = "lineno" > 91< / span >   }< / div >
< div class = "line" > < a name = "l00092" > < / a > < span class = "lineno" > 92< / span >   < / div >
< div class = "line" > < a name = "l00093" > < / a > < span class = "lineno" > 93< / span >   < span class = "keywordtype" > bool< / span > H264BitReader::HasMoreRBSPData() {< / div >
< div class = "line" > < a name = "l00094" > < / a > < span class = "lineno" > 94< / span >   < span class = "comment" > // Make sure we have more bits, if we are at 0 bits in current byte< / span > < / div >
< div class = "line" > < a name = "l00095" > < / a > < span class = "lineno" > 95< / span >   < span class = "comment" > // and updating current byte fails, we don' t have more data anyway.< / span > < / div >
< div class = "line" > < a name = "l00096" > < / a > < span class = "lineno" > 96< / span >   < span class = "keywordflow" > if< / span > (num_remaining_bits_in_curr_byte_ == 0 & & !UpdateCurrByte())< / div >
< div class = "line" > < a name = "l00097" > < / a > < span class = "lineno" > 97< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > false< / span > ;< / div >
< div class = "line" > < a name = "l00098" > < / a > < span class = "lineno" > 98< / span >   < / div >
< div class = "line" > < a name = "l00099" > < / a > < span class = "lineno" > 99< / span >   < span class = "comment" > // On last byte?< / span > < / div >
< div class = "line" > < a name = "l00100" > < / a > < span class = "lineno" > 100< / span >   < span class = "keywordflow" > if< / span > (bytes_left_)< / div >
< div class = "line" > < a name = "l00101" > < / a > < span class = "lineno" > 101< / span >   < span class = "keywordflow" > return< / span > < span class = "keyword" > true< / span > ;< / div >
< div class = "line" > < a name = "l00102" > < / a > < span class = "lineno" > 102< / span >   < / div >
< div class = "line" > < a name = "l00103" > < / a > < span class = "lineno" > 103< / span >   < span class = "comment" > // Last byte, look for stop bit;< / span > < / div >
< div class = "line" > < a name = "l00104" > < / a > < span class = "lineno" > 104< / span >   < span class = "comment" > // We have more RBSP data if the last non-zero bit we find is not the< / span > < / div >
< div class = "line" > < a name = "l00105" > < / a > < span class = "lineno" > 105< / span >   < span class = "comment" > // first available bit.< / span > < / div >
< div class = "line" > < a name = "l00106" > < / a > < span class = "lineno" > 106< / span >   < span class = "keywordflow" > return< / span > (curr_byte_ & < / div >
< div class = "line" > < a name = "l00107" > < / a > < span class = "lineno" > 107< / span >   ((1 < < (num_remaining_bits_in_curr_byte_ - 1)) - 1)) != 0;< / div >
< div class = "line" > < a name = "l00108" > < / a > < span class = "lineno" > 108< / span >   }< / div >
< div class = "line" > < a name = "l00109" > < / a > < span class = "lineno" > 109< / span >   < / div >
< div class = "line" > < a name = "l00110" > < / a > < span class = "lineno" > 110< / span >   < span class = "keywordtype" > size_t< / span > H264BitReader::NumEmulationPreventionBytesRead() {< / div >
< div class = "line" > < a name = "l00111" > < / a > < span class = "lineno" > 111< / span >   < span class = "keywordflow" > return< / span > emulation_prevention_bytes_;< / div >
< div class = "line" > < a name = "l00112" > < / a > < span class = "lineno" > 112< / span >   }< / div >
< div class = "line" > < a name = "l00113" > < / a > < span class = "lineno" > 113< / span >   < / div >
< div class = "line" > < a name = "l00114" > < / a > < span class = "lineno" > 114< / span >   } < span class = "comment" > // namespace media< / span > < / div >
< div class = "line" > < a name = "l00115" > < / a > < span class = "lineno" > 115< / span >   } < span class = "comment" > // namespace edash_packager< / span > < / div >
< / div > <!-- fragment --> < / div > <!-- contents -->
<!-- start footer part -->
< hr class = "footer" / > < address class = "footer" > < small >
2015-12-10 20:52:43 +00:00
Generated on Thu Dec 10 2015 20:52:36 for DASH Media Packaging SDK by   < a href = "http://www.doxygen.org/index.html" >
2015-10-16 00:33:37 +00:00
< img class = "footer" src = "../../doxygen.png" alt = "doxygen" / >
< / a > 1.8.6
< / small > < / address >
< / body >
< / html >
