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+Todo
+
+-- For other people
+- Multithread vc1.
+- Multithread an intra codec like mjpeg (trivial).
+- Fix mpeg1 (see below).
+- Try the first three items under Optimization.
+- Fix h264 (see below).
+- Try mpeg4 (see below).
+
+-- Bug fixes
+
+General critical:
+- Error resilience has to run before ff_report_frame_progress()
+is called. Otherwise there will be race conditions. (This might already
+work.) In general testing error paths should be done more.
+- 'make fate THREADS=2' doesn't pass. Most failures are due to
+bugs in vsync in ffmpeg.c, which are currently obscuring real failures.
+
+h264:
+- Files that aren't parsed (e.g. mp4) and contain PAFF with two
+field pictures in the same packet are not optimal. Modify the
+nals_needed check so that the second field's first slice is
+considered as needed, then uncomment the FIXME code in decode_postinit.
+Ex: http://astrange.ithinksw.net/ffmpeg/mt-samples/PAFF-Chalet-Tire.mp4
+
+mpeg4:
+- Packed B-frames need to be explicitly split up
+when frame threading is on. It's not very fast
+without this.
+- The buffer age optimization is disabled due to
+the way buffers are allocated across threads. The
+branch 'fix_buffer_age' has an attempt to fix it
+which breaks ffplay.
+- Support interlaced.
+
+mpeg1/2:
+- Seeking always prints "first frame not a keyframe"
+with threads on. Currently disabled for this reason.
+
+-- Prove correct
+
+- decode_update_progress() in h264.c
+race_checking branch has some work on h264,
+but not that function. It might be worth putting
+the branch under #ifdef DEBUG in mainline, but
+the code would have to be cleaner.
+- MPV_lowest_referenced_row() and co in mpegvideo.c
+- Same in vp3.
+
+-- Optimization
+
+- Merge h264 decode_update_progress() with loop_filter().
+Add CODEC_CAP_DRAW_HORIZ_BAND as a side effect.
+- EMU_EDGE is always set for h264 PAFF+MT
+because draw_edges() writes into the other field's
+thread's pixels. Needs an option to skip T/B fields.
+- Check update_thread_context() functions and make
+sure they only copy what they need to.
+- Try some more optimization of the "ref < 48; ref++"
+loop in h264.c await_references(), try turning the list0/list1 check
+above into a loop without being slower.
+- Support frame+slice threading at the same time
+by assigning slice_count threads for frame threads
+to use with execute(). This is simpler but unbalanced
+if only one frame thread uses any.
+
+-- Features
+
+- Support streams with width/height changing. This
+requires flushing all current frames (and buffering
+the input in the meantime), closing the codec and
+reopening it. Or don't support it.
+- Support encoding. Might need more threading primitives
+for good ratecontrol; would be nice for audio and libavfilter too.
+- Async decoding part 1: instead of trying to
+start every thread at the beginning, return a picture
+if the earliest thread is already done, but don't wait
+for it. Not sure what effect this would have.
+- Part 2: have an API that doesn't wait for the decoding
+thread, only returns EAGAIN if it's not ready. What will
+it do with the next input packet if it returns that?
+- Have an API that returns finished pictures but doesn't
+require sending new ones. Maybe allow NULL avpkt when
+not at the end of the stream.
+
+-- Samples
+
+http://astrange.ithinksw.net/ffmpeg/mt-samples/
+
+See yuvcmp.c in this directory to compare decoded samples.
+
+For debugging, try commenting out ff_thread_finish_setup calls so
+that only one thread runs at once, and then binary search+
+scatter printfs to look for differences in codec contexts.