Maintain a separate indexing from track_id to index to allow for non continues track ids (#43) (#58)

examples/mp4copy.rs

@@ -49,45 +49,42 @@ fn copy<P: AsRef<Path>>(src_filename: &P, dst_filename: &P) -> Result<()> {
     )?;
 
     // TODO interleaving
-    for track_idx in 0..mp4_reader.tracks().len() {
-        if let Some(ref track) = mp4_reader.tracks().get(track_idx) {
-            let media_conf = match track.media_type()? {
-                MediaType::H264 => MediaConfig::AvcConfig(AvcConfig {
-                    width: track.width(),
-                    height: track.height(),
-                    seq_param_set: track.sequence_parameter_set()?.to_vec(),
-                    pic_param_set: track.picture_parameter_set()?.to_vec(),
-                }),
-                MediaType::H265 => MediaConfig::HevcConfig(HevcConfig {
-                    width: track.width(),
-                    height: track.height(),
-                }),
-                MediaType::VP9 => MediaConfig::Vp9Config(Vp9Config {
-                    width: track.width(),
-                    height: track.height(),
-                }),
-                MediaType::AAC => MediaConfig::AacConfig(AacConfig {
-                    bitrate: track.bitrate(),
-                    profile: track.audio_profile()?,
-                    freq_index: track.sample_freq_index()?,
-                    chan_conf: track.channel_config()?,
-                }),
-                MediaType::TTXT => MediaConfig::TtxtConfig(TtxtConfig {}),
-            };
+    for track in mp4_reader.tracks().values() {
+        let media_conf = match track.media_type()? {
+            MediaType::H264 => MediaConfig::AvcConfig(AvcConfig {
+                width: track.width(),
+                height: track.height(),
+                seq_param_set: track.sequence_parameter_set()?.to_vec(),
+                pic_param_set: track.picture_parameter_set()?.to_vec(),
+            }),
+            MediaType::H265 => MediaConfig::HevcConfig(HevcConfig {
+                width: track.width(),
+                height: track.height(),
+            }),
+            MediaType::VP9 => MediaConfig::Vp9Config(Vp9Config {
+                width: track.width(),
+                height: track.height(),
+            }),
+            MediaType::AAC => MediaConfig::AacConfig(AacConfig {
+                bitrate: track.bitrate(),
+                profile: track.audio_profile()?,
+                freq_index: track.sample_freq_index()?,
+                chan_conf: track.channel_config()?,
+            }),
+            MediaType::TTXT => MediaConfig::TtxtConfig(TtxtConfig {}),
+        };
 
-            let track_conf = TrackConfig {
-                track_type: track.track_type()?,
-                timescale: track.timescale(),
-                language: track.language().to_string(),
-                media_conf,
-            };
+        let track_conf = TrackConfig {
+            track_type: track.track_type()?,
+            timescale: track.timescale(),
+            language: track.language().to_string(),
+            media_conf,
+        };
 
-            mp4_writer.add_track(&track_conf)?;
-        } else {
-            unreachable!()
-        }
+        mp4_writer.add_track(&track_conf)?;
+    }
 
-        let track_id = track_idx as u32 + 1;
+    for track_id in mp4_reader.tracks().keys().copied().collect::<Vec<u32>>() {
         let sample_count = mp4_reader.sample_count(track_id)?;
         for sample_idx in 0..sample_count {
             let sample_id = sample_idx + 1;

examples/mp4dump.rs

@@ -61,7 +61,7 @@ fn get_boxes(file: File) -> Result<Vec<Box>> {
     }
 
     // trak.
-    for track in mp4.tracks().iter() {
+    for track in mp4.tracks().values() {
         boxes.push(build_box(&track.trak));
         boxes.push(build_box(&track.trak.tkhd));
         if let Some(ref edts) = track.trak.edts {

examples/mp4info.rs

@@ -44,7 +44,7 @@ fn info<P: AsRef<Path>>(filename: &P) -> Result<()> {
     println!("  timescale:      {:?}\n", mp4.timescale());
 
     println!("Found {} Tracks", mp4.tracks().len());
-    for track in mp4.tracks().iter() {
+    for track in mp4.tracks().values() {
         let media_info = match track.track_type()? {
             TrackType::Video => video_info(track)?,
             TrackType::Audio => audio_info(track)?,

examples/mp4sample.rs

@@ -26,8 +26,7 @@ fn samples<P: AsRef<Path>>(filename: &P) -> Result<()> {
 
     let mut mp4 = mp4::Mp4Reader::read_header(reader, size)?;
 
-    for track_idx in 0..mp4.tracks().len() {
-        let track_id = track_idx as u32 + 1;
+    for track_id in mp4.tracks().keys().copied().collect::<Vec<u32>>() {
         let sample_count = mp4.sample_count(track_id).unwrap();
 
         for sample_idx in 0..sample_count {

examples/simple.rs

@@ -16,7 +16,7 @@ fn main() {
 
     println!("Major Brand: {}", mp4.major_brand());
 
-    for track in mp4.tracks().iter() {
+    for track in mp4.tracks().values() {
         println!("Track: #{}({}) {} {}",
             track.track_id(),
             track.language(),

src/lib.rs

@@ -37,7 +37,7 @@
 //!     println!("duration: {:?}", mp4.duration());
 //!
 //!    // Track info.
-//!    for track in mp4.tracks().iter() {
+//!    for track in mp4.tracks().values() {
 //!        println!(
 //!            "track: #{}({}) {} : {}",
 //!            track.track_id(),

src/reader.rs

@@ -1,8 +1,9 @@
+use std::collections::HashMap;
 use std::io::{Read, Seek, SeekFrom};
 use std::time::Duration;
 
-use crate::mp4box::*;
 use crate::*;
+use crate::mp4box::*;
 
 #[derive(Debug)]
 pub struct Mp4Reader<R> {
@@ -11,7 +12,7 @@ pub struct Mp4Reader<R> {
     pub moov: MoovBox,
     pub moofs: Vec<MoofBox>,
 
-    tracks: Vec<Mp4Track>,
+    tracks: HashMap<u32, Mp4Track>,
     size: u64,
 }
 
@@ -64,16 +65,14 @@ impl<R: Read + Seek> Mp4Reader<R> {
 
         let size = current - start;
         let mut tracks = if let Some(ref moov) = moov {
-            let mut tracks = Vec::with_capacity(moov.traks.len());
-            for (i, trak) in moov.traks.iter().enumerate() {
-                if trak.tkhd.track_id != i as u32 + 1 {
-                    return Err(Error::InvalidData("tracks out of order"));
-                }
-                tracks.push(Mp4Track::from(trak));
+            if moov.traks.iter().any(|trak| trak.tkhd.track_id == 0) {
+                return Err(Error::InvalidData("illegal track id 0"));
             }
-            tracks
+            moov.traks.iter()
+                .map(|trak| (trak.tkhd.track_id, Mp4Track::from(trak)))
+                .collect()
         } else {
-            Vec::new()
+            HashMap::new()
         };
 
         // Update tracks if any fragmented (moof) boxes are found.
@@ -87,9 +86,13 @@ impl<R: Read + Seek> Mp4Reader<R> {
 
             for moof in moofs.iter() {
                 for traf in moof.trafs.iter() {
-                    let track_id = traf.tfhd.track_id as usize - 1;
-                    tracks[track_id].default_sample_duration = default_sample_duration;
-                    tracks[track_id].trafs.push(traf.clone());
+                    let track_id = traf.tfhd.track_id;
+                    if let Some(track) = tracks.get_mut(&track_id) {
+                        track.default_sample_duration = default_sample_duration;
+                        track.trafs.push(traf.clone())
+                    } else {
+                        return Err(Error::TrakNotFound(track_id));
+                    }
                 }
             }
         }
@@ -132,16 +135,12 @@ impl<R: Read + Seek> Mp4Reader<R> {
         self.moofs.len() != 0
     }
 
-    pub fn tracks(&self) -> &[Mp4Track] {
+    pub fn tracks(&self) -> &HashMap<u32, Mp4Track> {
         &self.tracks
     }
 
     pub fn sample_count(&self, track_id: u32) -> Result<u32> {
-        if track_id == 0 {
-            return Err(Error::TrakNotFound(track_id));
-        }
-
-        if let Some(track) = self.tracks.get(track_id as usize - 1) {
+        if let Some(track) = self.tracks.get(&track_id) {
             Ok(track.sample_count())
         } else {
             Err(Error::TrakNotFound(track_id))
@@ -149,11 +148,7 @@ impl<R: Read + Seek> Mp4Reader<R> {
     }
 
     pub fn read_sample(&mut self, track_id: u32, sample_id: u32) -> Result<Option<Mp4Sample>> {
-        if track_id == 0 {
-            return Err(Error::TrakNotFound(track_id));
-        }
-
-        if let Some(ref track) = self.tracks.get(track_id as usize - 1) {
+        if let Some(track) = self.tracks.get(&track_id) {
             track.read_sample(&mut self.reader, sample_id)
         } else {
             Err(Error::TrakNotFound(track_id))

tests/lib.rs

@@ -94,7 +94,7 @@ fn test_read_mp4() {
     assert!(eos.is_none());
 
     // track #1
-    let track1 = mp4.tracks().get(0).unwrap();
+    let track1 = mp4.tracks().get(&1).unwrap();
     assert_eq!(track1.track_id(), 1);
     assert_eq!(track1.track_type().unwrap(), TrackType::Video);
     assert_eq!(track1.media_type().unwrap(), MediaType::H264);
@@ -105,7 +105,7 @@ fn test_read_mp4() {
     assert_eq!(track1.frame_rate(), 25.00); // XXX
 
     // track #2
-    let track2 = mp4.tracks().get(1).unwrap();
+    let track2 = mp4.tracks().get(&2).unwrap();
     assert_eq!(track2.track_type().unwrap(), TrackType::Audio);
     assert_eq!(track2.media_type().unwrap(), MediaType::AAC);
     assert_eq!(