From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- dom/media/XiphExtradata.cpp | 77 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 dom/media/XiphExtradata.cpp (limited to 'dom/media/XiphExtradata.cpp') diff --git a/dom/media/XiphExtradata.cpp b/dom/media/XiphExtradata.cpp new file mode 100644 index 0000000000..ff8ea1901d --- /dev/null +++ b/dom/media/XiphExtradata.cpp @@ -0,0 +1,77 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "XiphExtradata.h" + +namespace mozilla { + +bool XiphHeadersToExtradata(MediaByteBuffer* aCodecSpecificConfig, + const nsTArray& aHeaders, + const nsTArray& aHeaderLens) { + size_t nheaders = aHeaders.Length(); + if (!nheaders || nheaders > 255) return false; + aCodecSpecificConfig->AppendElement(nheaders - 1); + for (size_t i = 0; i < nheaders - 1; i++) { + size_t headerLen; + for (headerLen = aHeaderLens[i]; headerLen >= 255; headerLen -= 255) { + aCodecSpecificConfig->AppendElement(255); + } + aCodecSpecificConfig->AppendElement(headerLen); + } + for (size_t i = 0; i < nheaders; i++) { + aCodecSpecificConfig->AppendElements(aHeaders[i], aHeaderLens[i]); + } + return true; +} + +bool XiphExtradataToHeaders(nsTArray& aHeaders, + nsTArray& aHeaderLens, unsigned char* aData, + size_t aAvailable) { + size_t total = 0; + if (aAvailable < 1) { + return false; + } + aAvailable--; + int nHeaders = *aData++ + 1; + for (int i = 0; i < nHeaders - 1; i++) { + size_t headerLen = 0; + for (;;) { + // After this test, we know that (aAvailable - total > headerLen) and + // (headerLen >= 0) so (aAvailable - total > 0). The loop decrements + // aAvailable by 1 and total remains fixed, so we know that in the next + // iteration (aAvailable - total >= 0). Thus (aAvailable - total) can + // never underflow. + if (aAvailable - total <= headerLen) { + return false; + } + // Since we know (aAvailable > total + headerLen), this can't overflow + // unless total is near 0 and both aAvailable and headerLen are within + // 255 bytes of the maximum representable size. However, that is + // impossible, since we would have had to have gone through this loop + // more than 255 times to make headerLen that large, and thus decremented + // aAvailable more than 255 times. + headerLen += *aData; + aAvailable--; + if (*aData++ != 255) break; + } + // And this check ensures updating total won't cause (aAvailable - total) + // to underflow. + if (aAvailable - total < headerLen) { + return false; + } + aHeaderLens.AppendElement(headerLen); + // Since we know aAvailable >= total + headerLen, this can't overflow. + total += headerLen; + } + aHeaderLens.AppendElement(aAvailable - total); + for (int i = 0; i < nHeaders; i++) { + aHeaders.AppendElement(aData); + aData += aHeaderLens[i]; + } + return true; +} + +} // namespace mozilla -- cgit v1.2.3