feat(media): add bounded PCM capture, owned snapshots and A/V streaming

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packages/audio/src/io/native_capture.zigmodified+1-2

Changes to packages/audio/src/io/native_capture.zig

		@@ -1,6 +1,5 @@
1	1	//! Home opaque, header-checked ALSA capture. Build C boundary and link libasound.
2	2	//! Calls serialize; close only after read returns. S16LE mono/stereo, BOOTTIME ns.
3		-const std = ;
4	3	const Handle = opaque {};
5	4	pub const Config = extern struct { sample_rate: u32, channels: u32, block_frames: u32 };
6	5	extern fn home_audio_open(*const Config, [*:0]const u8, *?*Handle) c_int;
		⋯16 linesShow the 16 lines above this hunk@@ -23,7 +22,7 @@ pub const Capture = struct {
23	22	if (s.failed) return error.CaptureFailed;
24	23	if (data.len < @as(u64, s.config.block_frames) * s.config.channels * 2 or timeout_ms > 1000) return error.InvalidConfiguration;
25	24	var block: Block = undefined;
26		- const rc = home_audio_read(s.handle, data.ptr, @intCast(data.len / (s.config.channels * 2)), timeout_ms, &block.frames, &block.timestamp_ns, &block.clock_error_ns);
	25	+ const rc = home_audio_read(s.handle, data.ptr, @intCast(s.config.block_frames), timeout_ms, &block.frames, &block.timestamp_ns, &block.clock_error_ns);
27	26	if (rc == 1) return null;
28	27	check(rc) catch |err| {
29	28	s.failed = true;

packages/video/src/core/pcm_timeline.zigmodified+5-7

Changes to packages/video/src/core/pcm_timeline.zig

		⋯41 linesShow the 41 lines above this hunk@@ -42,13 +42,8 @@ pub const Queue = struct {
42	42	if (data.len == 0 or data.len % stride != 0) return error.InvalidPcm;
43	43	const frames = data.len / stride;
44	44	if (frames > s.capacity - s.used or s.count == s.entries.len) return error.BufferFull;
45		- var ts = timestamp;
46		- if (s.last_end) |end| {
47		- if (ts < end) {
48		- if (end - ts > (1_000_000_000 + s.rate - 1) / s.rate) return error.InvalidTimestamp;
49		- ts = end;
50		- }
51		- }
	45	+ const ts = timestamp;
	46	+ if (s.last_end) |end| if (ts < end) return error.InvalidTimestamp;
52	47	const end = try at(ts, frames, s.rate);
53	48	const first = @min(frames, s.capacity - s.write_pos);
54	49	@memcpy(s.data[s.write_pos * stride ..][0 .. first * stride], data[0 .. first * stride]);
		⋯60 linesShow the 60 lines above this hunk@@ -115,6 +110,9 @@ test "PCM rejects full queues, invalid inputs and overflow before modifying hist
115	110	try std.testing.expectError(error.InvalidPcm, q.push(&.{1}, 2000000));
116	111	try std.testing.expectError(error.InvalidTimestamp, q.push(&.{ 1, 0 }, 1));
117	112	try std.testing.expectError(error.TimestampOverflow, at(std.math.maxInt(u64), 1, 48000));
	113	+ const previous = q.last_end.?;
	114	+ try std.testing.expectError(error.InvalidTimestamp, q.push(&.{ 1, 0 }, previous - 1));
	115	+ try std.testing.expectEqual(previous, q.last_end.?);
118	116	try std.testing.expectEqual(@as(u64, 1_000_000_000), try at(0, 44100, 44100));
119	117	}
120	118	test "PCM partial allocation failure cleanup" {