Unknown app1

src/decoder.rs

@@ -4,7 +4,7 @@ use crate::marker::Marker;
 use crate::parser::{
     parse_app, parse_com, parse_dht, parse_dqt, parse_dri, parse_sof, parse_sos,
     AdobeColorTransform, AppData, CodingProcess, Component, Dimensions, EntropyCoding, FrameInfo,
-    IccChunk, ScanInfo,
+    IccChunk, ScanInfo, AppSegment,
 };
 use crate::read_u8;
 use crate::upsampler::Upsampler;
@@ -118,6 +118,7 @@ pub struct Decoder<R> {
     icc_markers: Vec<IccChunk>,
 
     exif_data: Option<Vec<u8>>,
+    app_segments: Vec<AppSegment>,
 
     // Used for progressive JPEGs.
     coefficients: Vec<Vec<i16>>,
@@ -144,6 +145,7 @@ impl<R: Read> Decoder<R> {
             is_mjpeg: false,
             icc_markers: Vec::new(),
             exif_data: None,
+            app_segments: Vec::new(),
             coefficients: Vec::new(),
             coefficients_finished: [0; MAX_COMPONENTS],
             decoding_buffer_size_limit: usize::MAX,
@@ -197,6 +199,11 @@ impl<R: Read> Decoder<R> {
         self.exif_data.as_deref()
     }
 
+    /// Returns collection of all captured app segments
+    pub fn app_segments(&self) -> &[AppSegment] {
+        self.app_segments.as_slice()
+    }
+
     /// Returns the embeded icc profile if the image contains one.
     pub fn icc_profile(&self) -> Option<Vec<u8>> {
         let mut marker_present: [Option<&IccChunk>; 256] = [None; 256];
@@ -520,7 +527,10 @@ impl<R: Read> Decoder<R> {
                 }
                 // Application data
                 Marker::APP(..) => {
-                    if let Some(data) = parse_app(&mut self.reader, marker)? {
+                    let (app_segment, app_data) = parse_app(&mut self.reader, marker)?;
+                    self.app_segments.push(app_segment);
+
+                    if let Some(data) = app_data {
                         match data {
                             AppData::Adobe(color_transform) => {
                                 self.adobe_color_transform = Some(color_transform)

src/parser.rs

@@ -2,7 +2,7 @@ use alloc::borrow::ToOwned;
 use alloc::{format, vec};
 use alloc::vec::Vec;
 use core::ops::{self, Range};
-use std::io::{self, Read};
+use std::io::Read;
 use crate::{read_u16_from_be, read_u8};
 use crate::error::{Error, Result, UnsupportedFeature};
 use crate::huffman::{HuffmanTable, HuffmanTableClass};
@@ -88,6 +88,12 @@ pub struct Component {
     pub block_size: Dimensions,
 }
 
+#[derive(Debug)]
+pub struct AppSegment {
+    pub kind: u8,
+    pub data: Vec<u8>,
+}
+
 #[derive(Debug)]
 pub enum AppData {
     Adobe(AdobeColorTransform),
@@ -143,17 +149,6 @@ fn read_length<R: Read>(reader: &mut R, marker: Marker) -> Result<usize> {
     Ok(length - 2)
 }
 
-fn skip_bytes<R: Read>(reader: &mut R, length: usize) -> Result<()> {
-    let length = length as u64;
-    let to_skip = &mut reader.by_ref().take(length);
-    let copied = io::copy(to_skip, &mut io::sink())?;
-    if copied < length {
-        Err(Error::Io(io::ErrorKind::UnexpectedEof.into()))
-    } else {
-        Ok(())
-    }
-}
-
 // Section B.2.2
 pub fn parse_sof<R: Read>(reader: &mut R, marker: Marker) -> Result<FrameInfo> {
     let length = read_length(reader, marker)?;
@@ -600,86 +595,66 @@ pub fn parse_com<R: Read>(reader: &mut R) -> Result<Vec<u8>> {
 }
 
 // Section B.2.4.6
-pub fn parse_app<R: Read>(reader: &mut R, marker: Marker) -> Result<Option<AppData>> {
+pub fn parse_app<R: Read>(reader: &mut R, marker: Marker) -> Result<(AppSegment, Option<AppData>)> {
     let length = read_length(reader, marker)?;
-    let mut bytes_read = 0;
+    let mut data = vec![0u8; length];
+
+    reader.read_exact(&mut data)?;
+
     let mut result = None;
 
     match marker {
         APP(0) => {
-            if length >= 5 {
-                let mut buffer = [0u8; 5];
-                reader.read_exact(&mut buffer)?;
-                bytes_read = buffer.len();
-
-                // http://www.w3.org/Graphics/JPEG/jfif3.pdf
-                if buffer[0..5] == *b"JFIF\0" {
-                    result = Some(AppData::Jfif);
-                // https://sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#AVI1
-                } else if buffer[0..5] == *b"AVI1\0" {
-                    result = Some(AppData::Avi1);
-                }
+            // http://www.w3.org/Graphics/JPEG/jfif3.pdf
+            if length >= 5 && data[0..5] == *b"JFIF\0" {
+                result = Some(AppData::Jfif);
+            // https://sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#AVI1
+            } else if length >= 5 && data[0..5] == *b"AVI1\0" {
+                result = Some(AppData::Avi1);
             }
         }
         // Exif Data
         APP(1) => {
-            if length >= 6 {
-                let mut buffer = [0u8; 6];
-                reader.read_exact(&mut buffer)?;
-                bytes_read = buffer.len();
-
-                // https://web.archive.org/web/20190624045241if_/http://www.cipa.jp:80/std/documents/e/DC-008-Translation-2019-E.pdf
-                // 4.5.4 Basic Structure of JPEG Compressed Data
-                if buffer == *b"Exif\x00\x00" {
-                    let mut data = vec![0; length - bytes_read];
-                    reader.read_exact(&mut data)?;
-                    bytes_read += data.len();
-                    result = Some(AppData::Exif(data));
-                }
+            // https://web.archive.org/web/20190624045241if_/http://www.cipa.jp:80/std/documents/e/DC-008-Translation-2019-E.pdf
+            // 4.5.4 Basic Structure of JPEG Compressed Data
+            if length >= 6 && &data[0..6] == *b"Exif\x00\x00" {
+                result = Some(AppData::Exif(data[6..].to_vec()));
             }
         }
         APP(2) => {
-            if length > 14 {
-                let mut buffer = [0u8; 14];
-                reader.read_exact(&mut buffer)?;
-                bytes_read = buffer.len();
-
-                // http://www.color.org/ICC_Minor_Revision_for_Web.pdf
-                // B.4 Embedding ICC profiles in JFIF files
-                if buffer[0..12] == *b"ICC_PROFILE\0" {
-                    let mut data = vec![0; length - bytes_read];
-                    reader.read_exact(&mut data)?;
-                    bytes_read += data.len();
-                    result = Some(AppData::Icc(IccChunk {
-                        seq_no: buffer[12],
-                        num_markers: buffer[13],
-                        data,
-                    }));
-                }
+            // http://www.color.org/ICC_Minor_Revision_for_Web.pdf
+            // B.4 Embedding ICC profiles in JFIF files
+            if length >= 12 && &data[0..12] == *b"ICC_PROFILE\0" {
+                result = Some(AppData::Icc(IccChunk {
+                    seq_no: data[12],
+                    num_markers: data[13],
+                    data: data[14..].to_vec(),
+                }));
             }
         }
         APP(14) => {
-            if length >= 12 {
-                let mut buffer = [0u8; 12];
-                reader.read_exact(&mut buffer)?;
-                bytes_read = buffer.len();
-
+            if length >= 12 && &data[0..6] == *b"Adobe\0" {
                 // http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html#Adobe
-                if buffer[0 .. 6] == *b"Adobe\0" {
-                    let color_transform = match buffer[11] {
-                        0 => AdobeColorTransform::Unknown,
-                        1 => AdobeColorTransform::YCbCr,
-                        2 => AdobeColorTransform::YCCK,
-                        _ => return Err(Error::Format("invalid color transform in adobe app segment".to_owned())),
-                    };
-
-                    result = Some(AppData::Adobe(color_transform));
-                }
+                let color_transform = match &data[11] {
+                    0 => AdobeColorTransform::Unknown,
+                    1 => AdobeColorTransform::YCbCr,
+                    2 => AdobeColorTransform::YCCK,
+                    _ => return Err(Error::Format("invalid color transform in adobe app segment".to_owned())),
+                };
+
+                result = Some(AppData::Adobe(color_transform));
             }
         },
         _ => {},
     }
 
-    skip_bytes(reader, length - bytes_read)?;
-    Ok(result)
+    let app_segment = AppSegment {
+        kind: match marker {
+            APP(kind) => kind,
+            _ => return Err(Error::Format("non APP marker".to_owned()))
+        },
+        data
+    };
+
+    Ok((app_segment, result))
 }

tests/lib.rs

@@ -154,3 +154,24 @@ fn read_exif_data() {
     // exif data start as a TIFF header
     assert_eq!(&exif_data[0..8], b"\x49\x49\x2A\x00\x08\x00\x00\x00");
 }
+
+#[test]
+fn read_app_segments() {
+    let path = Path::new("tests")
+        .join("reftest")
+        .join("images")
+        .join("ycck.jpg");
+
+    let mut decoder = jpeg::Decoder::new(File::open(&path).unwrap());
+    decoder.decode().unwrap();
+
+    let segments = decoder.app_segments();
+
+    // search for xmp data
+    assert!(segments
+        .into_iter()
+        .find(|segment| { segment.kind == 1 && segment.data.starts_with(b"http://ns.adobe.com/xap/1.0/") })
+        .is_some()
+    );
+    assert_eq!(segments.len(), 22);
+}