This fixes two separate issues. First, with the MSVC _snprintf implementations, the return value is negative if the buffer wasn't large enough - this would in the worst case lead to making iBufferUsed negative, writing before the start of the buffer. Secondly, when both iBufferUsed and iBufferLeft are accumulated, one can't do "iBufferLeft -= iBufferUsed;". As an example, say the buffer is 100 bytes in total and iBufferLeft is 40 and iBufferUsed is 60. If SNPRINTF then writes 5 more bytes to the buffer, iBufferUsed would be 65, but if we now do "iBufferLeft -= iBufferUsed;" then iBufferLeft would end up as -25 even though there's 35 bytes left in the buffer to use. Therefore, we use a separate variable to store the return value from the latest SNPRINTF call. This is checked to make sure it wasn't negative, and only this amount is added to iBufferUsed and subtracted from iBufferLeft. This is the same pattern used in codec/encoder/core/src/utils.cpp. strftime never returns negative numbers, so those calls don't need as much checking.
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| @@ -90,10 +90,12 @@ CWelsDecoder::CWelsDecoder (void_t) · 89 unmodified lines | ||
| 90 | 90 | str_t chFileName[1024] = { 0 }; //for .264 |
| 91 | 91 | int iBufUsed = 0; |
| 92 | 92 | int iBufLeft = 1023; |
| 93 | + int iCurUsed; | |
| 93 | 94 | |
| 94 | 95 | str_t chFileNameSize[1024] = { 0 }; //for .len |
| 95 | 96 | int iBufUsedSize = 0; |
| 96 | 97 | int iBufLeftSize = 1023; |
| 98 | + int iCurUsedSize; | |
| 97 | 99 | #endif//OUTPUT_BIT_STREAM |
| 98 | 100 | |
| 99 | 101 | m_pTrace = CreateWelsTrace (Wels_Trace_Type); |
| @@ -106,30 +108,44 @@ CWelsDecoder::CWelsDecoder (void_t) · 6 unmodified lines | ||
| 106 | 108 | |
| 107 | 109 | WelsGetTimeOfDay (&sCurTime); |
| 108 | 110 | |
| 109 | − iBufUsed += WelsSnprintf (chFileName, iBufLeft, "bs_0x%p_", (void_t*)this); | |
| 110 | − iBufUsedSize += WelsSnprintf (chFileNameSize, iBufLeftSize, "size_0x%p_", (void_t*)this); | |
| 111 | + iCurUsed = WelsSnprintf (chFileName, iBufLeft, "bs_0x%p_", (void_t*)this); | |
| 112 | + iCurUsedSize = WelsSnprintf (chFileNameSize, iBufLeftSize, "size_0x%p_", (void_t*)this); | |
| 111 | 113 | |
| 112 | − iBufLeft -= iBufUsed; | |
| 114 | + if (iCurUsed > 0) { | |
| 115 | + iBufUsed += iCurUsed; | |
| 116 | + iBufLeft -= iCurUsed; | |
| 117 | + } | |
| 113 | 118 | if (iBufLeft > 0) { |
| 114 | − iBufUsed += WelsStrftime (&chFileName[iBufUsed], iBufLeft, "%y%m%d%H%M%S", &sCurTime); | |
| 115 | − iBufLeft -= iBufUsed; | |
| 119 | + iCurUsed = WelsStrftime (&chFileName[iBufUsed], iBufLeft, "%y%m%d%H%M%S", &sCurTime); | |
| 120 | + iBufUsed += iCurUsed; | |
| 121 | + iBufLeft -= iCurUsed; | |
| 116 | 122 | } |
| 117 | 123 | |
| 118 | − iBufLeftSize -= iBufUsedSize; | |
| 124 | + if (iCurUsedSize > 0) { | |
| 125 | + iBufUsedSize += iCurUsedSize; | |
| 126 | + iBufLeftSize -= iCurUsedSize; | |
| 127 | + } | |
| 119 | 128 | if (iBufLeftSize > 0) { |
| 120 | − iBufUsedSize += WelsStrftime (&chFileNameSize[iBufUsedSize], iBufLeftSize, "%y%m%d%H%M%S", &sCurTime); | |
| 121 | − iBufLeftSize -= iBufUsedSize; | |
| 129 | + iCurUsedSize = WelsStrftime (&chFileNameSize[iBufUsedSize], iBufLeftSize, "%y%m%d%H%M%S", &sCurTime); | |
| 130 | + iBufUsedSize += iCurUsedSize; | |
| 131 | + iBufLeftSize -= iCurUsedSize; | |
| 122 | 132 | } |
| 123 | 133 | |
| 124 | 134 | if (iBufLeft > 0) { |
| 125 | − iBufUsed += WelsSnprintf (&chFileName[iBufUsed], iBufLeft, ".%03.3u.264", WelsGetMillsecond (&sCurTime)); | |
| 126 | − iBufLeft -= iBufUsed; | |
| 135 | + iCurUsed = WelsSnprintf (&chFileName[iBufUsed], iBufLeft, ".%03.3u.264", WelsGetMillsecond (&sCurTime)); | |
| 136 | + if (iCurUsed > 0) { | |
| 137 | + iBufUsed += iCurUsed; | |
| 138 | + iBufLeft -= iCurUsed; | |
| 139 | + } | |
| 127 | 140 | } |
| 128 | 141 | |
| 129 | 142 | if (iBufLeftSize > 0) { |
| 130 | − iBufUsedSize += WelsSnprintf (&chFileNameSize[iBufUsedSize], iBufLeftSize, ".%03.3u.len", | |
| 131 | − WelsGetMillsecond (&sCurTime)); | |
| 132 | − iBufLeftSize -= iBufUsedSize; | |
| 143 | + iCurUsedSize = WelsSnprintf (&chFileNameSize[iBufUsedSize], iBufLeftSize, ".%03.3u.len", | |
| 144 | + WelsGetMillsecond (&sCurTime)); | |
| 145 | + if (iCurUsedSize > 0) { | |
| 146 | + iBufUsedSize += iCurUsedSize; | |
| 147 | + iBufLeftSize -= iCurUsedSize; | |
| 148 | + } | |
| 133 | 149 | } |
| 134 | 150 | |
| 135 | 151 | |