diff --git a/CHANGELOG.md b/CHANGELOG.md index 0b3b0f98..9c0cd8be 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -1,3 +1,7 @@ +0.5.2 +===== +- AudioFlinger: optimize WAV volume scaling + 0.5.1 ===== - Fri3d Camp 2024 Board: add startup light and sound diff --git a/internal_filesystem/lib/mpos/audio/stream_wav.py b/internal_filesystem/lib/mpos/audio/stream_wav.py index e08261b5..84723800 100644 --- a/internal_filesystem/lib/mpos/audio/stream_wav.py +++ b/internal_filesystem/lib/mpos/audio/stream_wav.py @@ -3,6 +3,7 @@ # Ported from MusicPlayer's AudioPlayer class import machine +import micropython import os import time import sys @@ -10,7 +11,6 @@ import sys # Volume scaling function - Viper-optimized for ESP32 performance # NOTE: The line below is automatically commented out by build_mpos.sh during # Unix/macOS builds (cross-compiler doesn't support Viper), then uncommented after build. -import micropython @micropython.viper def _scale_audio(buf: ptr8, num_bytes: int, scale_fixed: int): """Fast volume scaling for 16-bit audio samples using Viper (ESP32 native code emitter).""" @@ -28,99 +28,46 @@ def _scale_audio(buf: ptr8, num_bytes: int, scale_fixed: int): buf[i] = sample & 255 buf[i + 1] = (sample >> 8) & 255 -import micropython @micropython.viper def _scale_audio_optimized(buf: ptr8, num_bytes: int, scale_fixed: int): - """ - Very fast 16-bit volume scaling using only shifts + adds. - - 100 % and above → no change - - < ~12.5 % → pure right-shift (fastest) - - otherwise → high-quality shift/add approximation - """ - if scale_fixed >= 32768: # 100 % or more + if scale_fixed >= 32768: return - if scale_fixed <= 0: # muted + if scale_fixed <= 0: for i in range(num_bytes): buf[i] = 0 return - # -------------------------------------------------------------- - # Very low volumes → simple right-shift (super cheap) - # -------------------------------------------------------------- - if scale_fixed < 4096: # < ~12.5 % - shift: int = 0 - tmp: int = 32768 - while tmp > scale_fixed: - shift += 1 - tmp >>= 1 - for i in range(0, num_bytes, 2): - lo: int = int(buf[i]) - hi: int = int(buf[i + 1]) - s: int = (hi << 8) | lo - if hi & 128: # sign extend - s -= 65536 - s >>= shift - buf[i] = s & 255 - buf[i + 1] = (s >> 8) & 255 - return + mask: int = scale_fixed - # -------------------------------------------------------------- - # Medium → high volumes: sample * scale_fixed // 32768 - # approximated with shifts + adds only - # -------------------------------------------------------------- - # Build a 16-bit mask: - # bit 0 → add (s >> 15) - # bit 1 → add (s >> 14) - # ... - # bit 15 → add s (>> 0) - mask: int = 0 - bit_value: int = 16384 # starts at 2^-1 - remaining: int = scale_fixed - - shift_idx: int = 1 # corresponds to >>1 - while bit_value > 0: - if remaining >= bit_value: - mask |= (1 << (16 - shift_idx)) # correct bit position - remaining -= bit_value - bit_value >>= 1 - shift_idx += 1 - - # Apply the mask for i in range(0, num_bytes, 2): - lo: int = int(buf[i]) - hi: int = int(buf[i + 1]) - s: int = (hi << 8) | lo - if hi & 128: - s -= 65536 + s: int = int(buf[i]) | (int(buf[i+1]) << 8) + if s >= 0x8000: + s -= 0x10000 - result: int = 0 - if mask & 0x8000: result += s # >>0 - if mask & 0x4000: result += (s >> 1) - if mask & 0x2000: result += (s >> 2) - if mask & 0x1000: result += (s >> 3) - if mask & 0x0800: result += (s >> 4) - if mask & 0x0400: result += (s >> 5) - if mask & 0x0200: result += (s >> 6) - if mask & 0x0100: result += (s >> 7) - if mask & 0x0080: result += (s >> 8) - if mask & 0x0040: result += (s >> 9) - if mask & 0x0020: result += (s >>10) - if mask & 0x0010: result += (s >>11) - if mask & 0x0008: result += (s >>12) - if mask & 0x0004: result += (s >>13) - if mask & 0x0002: result += (s >>14) - if mask & 0x0001: result += (s >>15) + r: int = 0 + if mask & 0x8000: r += s + if mask & 0x4000: r += s>>1 + if mask & 0x2000: r += s>>2 + if mask & 0x1000: r += s>>3 + if mask & 0x0800: r += s>>4 + if mask & 0x0400: r += s>>5 + if mask & 0x0200: r += s>>6 + if mask & 0x0100: r += s>>7 + if mask & 0x0080: r += s>>8 + if mask & 0x0040: r += s>>9 + if mask & 0x0020: r += s>>10 + if mask & 0x0010: r += s>>11 + if mask & 0x0008: r += s>>12 + if mask & 0x0004: r += s>>13 + if mask & 0x0002: r += s>>14 + if mask & 0x0001: r += s>>15 - # Clamp to 16-bit signed range - if result > 32767: - result = 32767 - elif result < -32768: - result = -32768 + if r > 32767: r = 32767 + if r < -32768: r = -32768 - buf[i] = result & 255 - buf[i + 1] = (result >> 8) & 255 + buf[i] = r & 0xFF + buf[i+1] = (r >> 8) & 0xFF -import micropython @micropython.viper def _scale_audio_rough(buf: ptr8, num_bytes: int, scale_fixed: int): """Rough volume scaling for 16-bit audio samples using right shifts for performance.""" @@ -375,9 +322,12 @@ class WAVStream: # smaller chunk size means less jerks but buffer can run empty # at 22050 Hz, 16-bit, 2-ch, 4096/4 = 1024 samples / 22050 = 46ms + # with rough volume scaling: # 4096 => audio stutters during quasibird # 8192 => no audio stutters and quasibird runs at ~16 fps => good compromise! # 16384 => no audio stutters during quasibird but low framerate (~8fps) + # with optimized volume scaling: + # 8192 => no audio stutters and quasibird runs at ~12fps chunk_size = 4096*2 bytes_per_original_sample = (bits_per_sample // 8) * channels total_original = 0 diff --git a/scripts/install.sh b/scripts/install.sh index 7dd15113..984121af 100755 --- a/scripts/install.sh +++ b/scripts/install.sh @@ -47,6 +47,8 @@ fi # The issue is that this brings all the .git folders with it: #$mpremote fs cp -r apps :/ +$mpremote fs cp -r lib :/ + $mpremote fs mkdir :/apps $mpremote fs cp -r apps/com.micropythonos.* :/apps/ find apps/ -maxdepth 1 -type l | while read symlink; do @@ -59,7 +61,6 @@ done #echo "Unmounting builtin/ so that it can be customized..." # not sure this is necessary #$mpremote exec "import os ; os.umount('/builtin')" $mpremote fs cp -r builtin :/ -$mpremote fs cp -r lib :/ #$mpremote fs cp -r data :/ #$mpremote fs cp -r data/images :/data/