1 files changed, 116 insertions, 0 deletions
diff --git a/remuxer/src/import/seek_index.rs b/remuxer/src/import/seek_index.rs
new file mode 100644
index 0000000..363a12f
--- /dev/null
+++ b/remuxer/src/import/seek_index.rs
@@ -0,0 +1,116 @@
+use anyhow::Result;
+use jellycommon::{BlockIndex, SeekIndex};
+use jellymatroska::{
+    block::Block,
+    read::EbmlReader,
+    unflatten::{IterWithPos, Unflat, Unflatten},
+    MatroskaTag,
+};
+use log::{debug, info, trace, warn};
+use std::collections::BTreeMap;
+
+pub fn import_seek_index(input: &mut EbmlReader) -> Result<BTreeMap<u64, SeekIndex>> {
+    let mut seek_index = BTreeMap::new();
+    while let Some(item) = input.next() {
+        let item = match item {
+            Ok(item) => item,
+            Err(e) => {
+                warn!("{e}");
+                break;
+            }
+        };
+        match item {
+            MatroskaTag::Segment(_) => {
+                info!("segment start");
+                let mut children = Unflatten::new_with_end(input, item);
+                import_seek_index_segment(&mut children, &mut seek_index)?;
+                info!("segment end");
+            }
+            _ => debug!("(r) tag ignored: {item:?}"),
+        }
+    }
+    Ok(seek_index)
+}
+
+fn import_seek_index_segment(
+    segment: &mut Unflatten,
+    seek_index: &mut BTreeMap<u64, SeekIndex>,
+) -> Result<()> {
+    while let Some(Ok(Unflat { children, item, .. })) = segment.n() {
+        match item {
+            MatroskaTag::SeekHead(_) => {}
+            MatroskaTag::Info(_) => {}
+            MatroskaTag::Tags(_) => {}
+            MatroskaTag::Cues(_) => {}
+            MatroskaTag::Chapters(_) => {}
+            MatroskaTag::Tracks(_) => {}
+            MatroskaTag::Cluster(_) => {
+                let mut children = children.unwrap();
+                let mut pts = 0;
+                let mut position = children.position();
+
+                loop {
+                    if let Some(Ok(Unflat { children, item, .. })) = children.n() {
+                        match item {
+                            MatroskaTag::Timestamp(ts) => pts = ts,
+                            MatroskaTag::BlockGroup(_) => {
+                                debug!("group");
+                                let mut children = children.unwrap();
+                                // let position = children.position(); //? TODO where should this point to? cluster or block? // probably block
+                                while let Some(Ok(Unflat {
+                                    children: _,
+                                    item,
+                                    position,
+                                })) = children.n()
+                                {
+                                    match item {
+                                        MatroskaTag::Block(ref buf) => {
+                                            let block = Block::parse(buf)?;
+                                            debug!(
+                                                "block: track={} tso={}",
+                                                block.track, block.timestamp_off
+                                            );
+                                            seek_index
+                                                .entry(block.track)
+                                                .or_insert(SeekIndex { blocks: vec![] })
+                                                .blocks
+                                                .push(BlockIndex {
+                                                    pts: pts + block.timestamp_off as u64,
+                                                    source_off: position,
+                                                    size: block.data.len(),
+                                                });
+                                        }
+                                        _ => trace!("{item:?}"),
+                                    }
+                                }
+                            }
+                            MatroskaTag::SimpleBlock(buf) => {
+                                let block = Block::parse(&buf)?;
+                                debug!(
+                                    "simple block: track={} tso={}",
+                                    block.track, block.timestamp_off
+                                );
+                                debug!("{pts} {}", block.timestamp_off);
+                                seek_index
+                                    .entry(block.track)
+                                    .or_insert(SeekIndex { blocks: vec![] })
+                                    .blocks
+                                    .push(BlockIndex {
+                                        pts: (pts as i64 + block.timestamp_off as i64) as u64,
+                                        source_off: position,
+                                        size: block.data.len(),
+                                    });
+                            }
+                            _ => debug!("(rsc) tag ignored: {item:?}"),
+                        }
+                    } else {
+                        break;
+                    }
+                    position = children.position();
+                }
+            }
+            _ => debug!("(rs) tag ignored: {item:?}"),
+        };
+    }
+    Ok(())
+}