diff options
author | Sam Whited <sam@samwhited.com> | 2014-10-30 15:20:20 -0400 |
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committer | Sam Whited <sam@samwhited.com> | 2014-10-30 15:33:13 -0400 |
commit | 46f147a82c6b161e071f717c7686f8b78a20aaf1 (patch) | |
tree | 38ee04006e38197fd8009697b8975007ec0f45c8 /src/main/java/eu/siacs/conversations/utils/ExifHelper.java | |
parent | 142384e5805d93887d185c9a5b74d4850e4ec719 (diff) | |
parent | a362bd10214b16f8939c12a1dd4376667fe0d49f (diff) |
Merge branch 'gradle' into development
Conflicts:
.gitignore
CHANGELOG.md
README.md
libs/MemorizingTrustManager
libs/minidns
libs/openpgp-api-lib
Diffstat (limited to 'src/main/java/eu/siacs/conversations/utils/ExifHelper.java')
-rw-r--r-- | src/main/java/eu/siacs/conversations/utils/ExifHelper.java | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/main/java/eu/siacs/conversations/utils/ExifHelper.java b/src/main/java/eu/siacs/conversations/utils/ExifHelper.java new file mode 100644 index 000000000..ceda72933 --- /dev/null +++ b/src/main/java/eu/siacs/conversations/utils/ExifHelper.java @@ -0,0 +1,161 @@ +/* + * Copyright (C) 2011 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package eu.siacs.conversations.utils; + +import android.util.Log; + +import java.io.IOException; +import java.io.InputStream; + +public class ExifHelper { + private static final String TAG = "CameraExif"; + + public static int getOrientation(InputStream is) { + if (is == null) { + return 0; + } + + byte[] buf = new byte[8]; + int length = 0; + + // ISO/IEC 10918-1:1993(E) + while (read(is, buf, 2) && (buf[0] & 0xFF) == 0xFF) { + int marker = buf[1] & 0xFF; + + // Check if the marker is a padding. + if (marker == 0xFF) { + continue; + } + + // Check if the marker is SOI or TEM. + if (marker == 0xD8 || marker == 0x01) { + continue; + } + // Check if the marker is EOI or SOS. + if (marker == 0xD9 || marker == 0xDA) { + return 0; + } + + // Get the length and check if it is reasonable. + if (!read(is, buf, 2)) { + return 0; + } + length = pack(buf, 0, 2, false); + if (length < 2) { + Log.e(TAG, "Invalid length"); + return 0; + } + length -= 2; + + // Break if the marker is EXIF in APP1. + if (marker == 0xE1 && length >= 6) { + if (!read(is, buf, 6)) return 0; + length -= 6; + if (pack(buf, 0, 4, false) == 0x45786966 && + pack(buf, 4, 2, false) == 0) { + break; + } + } + + // Skip other markers. + try { + is.skip(length); + } catch (IOException ex) { + return 0; + } + length = 0; + } + + // JEITA CP-3451 Exif Version 2.2 + if (length > 8) { + int offset = 0; + byte[] jpeg = new byte[length]; + if (!read(is, jpeg, length)) { + return 0; + } + + // Identify the byte order. + int tag = pack(jpeg, offset, 4, false); + if (tag != 0x49492A00 && tag != 0x4D4D002A) { + Log.e(TAG, "Invalid byte order"); + return 0; + } + boolean littleEndian = (tag == 0x49492A00); + + // Get the offset and check if it is reasonable. + int count = pack(jpeg, offset + 4, 4, littleEndian) + 2; + if (count < 10 || count > length) { + Log.e(TAG, "Invalid offset"); + return 0; + } + offset += count; + length -= count; + + // Get the count and go through all the elements. + count = pack(jpeg, offset - 2, 2, littleEndian); + while (count-- > 0 && length >= 12) { + // Get the tag and check if it is orientation. + tag = pack(jpeg, offset, 2, littleEndian); + if (tag == 0x0112) { + // We do not really care about type and count, do we? + int orientation = pack(jpeg, offset + 8, 2, littleEndian); + switch (orientation) { + case 1: + return 0; + case 3: + return 180; + case 6: + return 90; + case 8: + return 270; + } + Log.i(TAG, "Unsupported orientation"); + return 0; + } + offset += 12; + length -= 12; + } + } + + Log.i(TAG, "Orientation not found"); + return 0; + } + + private static int pack(byte[] bytes, int offset, int length, + boolean littleEndian) { + int step = 1; + if (littleEndian) { + offset += length - 1; + step = -1; + } + + int value = 0; + while (length-- > 0) { + value = (value << 8) | (bytes[offset] & 0xFF); + offset += step; + } + return value; + } + + private static boolean read(InputStream is, byte[] buf, int length) { + try { + return is.read(buf, 0, length) == length; + } catch (IOException ex) { + return false; + } + } +} |