Hi Josh, 1. Yes we are working on the example and have it defined as follows: https://github.com/JHBalaji/media/blob/master/examples/set_value_curve.rs
Can you tell us if the example we have defined is right? We have written it similar to the example you shared with us <https://developer.mozilla.org/en-US/docs/Web/API/AudioParam/setValueCurveAtTime> . 2. Our implementation of the SetValueCurveAtTime to this point is as follows: https://github.com/JHBalaji/media/blob/master/audio/src/param.rs#L419-L439 As you had mentioned earlier, can you/someone from your team verify if our function definition is right? (Specifically for the linear interpolation part, that's where we think the mistake is but not sure how to change it) as we are getting a few errors while trying to run the example. Error: Akhileshs-MBP:media akhilesh$ ./target/debug/set_value_curve thread 'AudioRenderThread' panicked at 'index out of bounds: the len is 9 but the index is 9', /rustc/94fd0458951a4ff91c03366445f0e2e93b86bd2f/src/libcore/slice/mod.rs:2539 :10 note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace. thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: RecvError', src/libcore/result.rs:997:5 Thanks Akhilesh On Sat, Mar 30, 2019 at 12:25 PM Josh Bowman-Matthews <j...@joshmatthews.net> wrote: > I think it is important that the pull request you make for your > assignment include example code that demonstrates that your > implementation works as expected. > > cheers, > Josh > > On 3/30/19 5:22 AM, Akhilesh Venkatasubramanian wrote: > > Hi Josh, > > > > I have addressed the same in my code right now. The code compiles and > > throws no errors now. This is the version that we have now: > > > https://github.com/JHBalaji/media/blob/master/audio/src/param.rs#L419-L433 > > > > Can you please see if this is fine? > > > > Also, we have a submission for this assignment on Monday so can we > submit a > > pull request with what we have till now? Also, we will continue to work > on > > Mozilla for our final semester project and considering that we have a > > better hang of how WebAudio works I think we can actively contribute. > > > > Thanks again for your valuable inputs, we are now able to understand the > > flow of code much better. > > > > - Akhilesh > > > > > > > > On Sat, Mar 30, 2019 at 12:27 AM Josh Bowman-Matthews < > j...@joshmatthews.net> > > wrote: > > > >> Answers inline: > >> > >> On 3/29/19 7:54 PM, Akhilesh Venkatasubramanian wrote: > >>> Hi Josh, > >>> > >>> We went ahead to try to implement the function and are facing some > issues > >>> and your insight will be helpful. > >>> > >>> 1. We have implemented the function here: > >>> > >>> > >> > https://github.com/JHBalaji/media/blob/master/audio/src/param.rs#L419-L434 > >>> < > >> > https://github.com/JHBalaji/media/blob/master/audio/src/param.rs#L419-L434 > >>> . > >>> > >>> A) Can you check if our implementation of interpolating between > v[k] > >> and > >>> v[k+1] is correct? If not, can you give us a heads up as to how to > >>> proceed? > >> > >> It took me a while to step through it and convince myself that it made > >> sense, but I think it's right. I'll probably ask one of our Web Audio > >> experts to double-check it. The naming of x1/x2 and y1/y2 did not help > >> me; I would suggest using names like v_k and v_k_next as well as time_k > >> and time_k_next to improve readability. > >> > >> > >>> The above code does give out a few errors as below: > >>> > >>> Compiling servo-media-audio v0.1.0 > >> (/Users/akhilesh/Desktop/media/audio) > >>> > >>> error[E0277]: cannot subtract `block::Tick` from `f32` > >>> > >>> --> audio/src/param.rs:432:37 > >>> > >>> | > >>> > >>> 432 | *value = (y1 * (x2 - current_tick) + y2 * > >>> (current_tick - x1)) / (x2 - x1) as f32; > >>> > >>> | ^ no implementation for > `f32 - > >>> block::Tick` > >>> > >>> | > >>> > >>> = help: the trait `std::ops::Sub<block::Tick>` is not implemented > >> for > >>> `f32` > >>> > >>> > >>> error[E0277]: cannot subtract `f32` from `block::Tick` > >>> > >>> --> audio/src/param.rs:432:74 > >>> > >>> | > >>> > >>> 432 | *value = (y1 * (x2 - current_tick) + y2 * > >>> (current_tick - x1)) / (x2 - x1) as f32; > >>> > >>> | > >>> ^ no implementation for `block::Tick - f32` > >>> > >>> | > >>> > >>> = help: the trait `std::ops::Sub<f32>` is not implemented for > >>> `block::Tick` > >>> > >>> > >>> error: aborting due to 2 previous errors > >>> > >>> I was not able to subtract current_tick from the value instance I > >> generated > >>> to keep track of the expected time for v[k] and v[k+1]. Can you give me > >>> some pointers as to how I can fix the same? > >> > >> You can find the documentation for block::Tick at > >> https://doc.servo.org/servo_media_audio/block/struct.Tick.html . If you > >> click the "Show Declaration", you will see that it wraps a u64 value, > >> which you can retrieve with `current_tick.0` and can then cast to f32. > >> > >> > >> > >> > >>> > >>> B) Should we declare the values vector and duration also somewhere else > >> in > >>> the program or are the changes made by me enough to handle the > function? > >>> > >>> 2. There was one more modification I had to make to make the code > compile > >>> till the previous point. In L259 > >>> <https://github.com/JHBalaji/media/blob/master/audio/src/param.rs#L259 > > > >> and > >>> L271, if I also had the Copy trait called then it shows the error > posted > >>> below, which I believe is because of the values vector in the > >>> SetValueCurveAtTime function. Can I just remove the copy trait or is > >> there > >>> any other modification that I have to make? > >>> > >>> error[E0204]: the trait `Copy` may not be implemented for this type > >>> > >>> --> audio/src/param.rs:259:17 > >>> > >>> | > >>> > >>> 259 | #[derive(Clone, Copy, PartialEq, Debug)] > >>> > >>> | ^^^^ > >>> > >>> ... > >>> > >>> 266 | SetValueCurveAtTime(Vec<f32>, Tick, /* duration */ f64), > >>> > >>> | -------- this field does not implement > >> `Copy` > >>> > >>> > >>> error[E0204]: the trait `Copy` may not be implemented for this type > >>> > >>> --> audio/src/param.rs:271:17 > >>> > >>> | > >>> > >>> 271 | #[derive(Clone, Copy, PartialEq, Debug)] > >>> > >>> | ^^^^ > >>> > >>> ... > >>> > >>> 278 | SetValueCurveAtTime(Vec<f32>, f64, /* duration */ f64), > >>> > >>> | -------- this field does not implement > >> `Copy` > >>> > >>> > >>> error: aborting due to 2 previous errors > >>> > >>> > >>> For more information about this error, try `rustc --explain E0204`. > >>> > >>> error: Could not compile `servo-media-audio`. > >>> > >>> This was apparently a problem for the group which worked with the > >>> Oscillator node last semester and they weren't able to implement the > >> custom > >>> method > >>> < > >> > https://github.com/servo/media/blob/master/audio/src/oscillator_node.rs#L150 > >>> > >>> because they weren't able to solve this issue and when I spoke to one > >>> person he said that removing the copy trait started showing up more > >> errors > >>> later. Can you give us your take on this? > >> > >> Removing the Copy trait is fine. Any code that relies on it can have an > >> explicit `.clone()` added to it and it should compile. > >> > >> Cheers, > >> Josh > >> _______________________________________________ > >> dev-servo mailing list > >> dev-servo@lists.mozilla.org > >> https://lists.mozilla.org/listinfo/dev-servo > >> > > _______________________________________________ > dev-servo mailing list > dev-servo@lists.mozilla.org > https://lists.mozilla.org/listinfo/dev-servo > _______________________________________________ dev-servo mailing list dev-servo@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-servo
