From 91c9d9ee8886da58372c4dc8df958e7f26d2ed05 Mon Sep 17 00:00:00 2001 From: Karol Kosek Date: Tue, 3 Aug 2021 20:06:18 +0200 Subject: [PATCH] LibAudio: Make playing lossy flacs more truthful Playing a lossy flac file resulted in hearing something you'd not like to play. Instead of your lovely bass, you had sounds as if you put a CD-ROM disc to a CD player. It turned out that the size for making signed values was too big, making all the values unsigned. I've used lossyWav[1] (the posix port[2] to be exact) to generate such files. [1]: https://wiki.hydrogenaud.io/index.php?title=LossyWAV [2]: https://github.com/MoSal/lossywav-for-posix --- Userland/Libraries/LibAudio/FlacLoader.cpp | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/Userland/Libraries/LibAudio/FlacLoader.cpp b/Userland/Libraries/LibAudio/FlacLoader.cpp index b79c9fa8f8..44f8671f01 100644 --- a/Userland/Libraries/LibAudio/FlacLoader.cpp +++ b/Userland/Libraries/LibAudio/FlacLoader.cpp @@ -596,7 +596,7 @@ Vector FlacLoaderPlugin::parse_subframe(FlacSubframeHeader& subframe_header samples.ensure_capacity(m_current_frame->sample_count); for (u32 i = 0; i < m_current_frame->sample_count; ++i) { - samples.unchecked_append(sign_extend(constant_value, subframe_header.bits_per_sample)); + samples.unchecked_append(sign_extend(constant_value, subframe_header.bits_per_sample - subframe_header.wasted_bits_per_sample)); } break; } @@ -645,8 +645,7 @@ Vector FlacLoaderPlugin::decode_custom_lpc(FlacSubframeHeader& subframe, In // warm-up samples for (auto i = 0; i < subframe.order; ++i) { - decoded.unchecked_append(sign_extend(bit_input.read_bits_big_endian(subframe.bits_per_sample - subframe.wasted_bits_per_sample), subframe.bits_per_sample)); - decoded[i] <<= subframe.wasted_bits_per_sample; + decoded.unchecked_append(sign_extend(bit_input.read_bits_big_endian(subframe.bits_per_sample - subframe.wasted_bits_per_sample), subframe.bits_per_sample - subframe.wasted_bits_per_sample)); } // precision of the coefficients @@ -695,7 +694,7 @@ Vector FlacLoaderPlugin::decode_fixed_lpc(FlacSubframeHeader& subframe, Inp // warm-up samples for (auto i = 0; i < subframe.order; ++i) { - decoded.unchecked_append(sign_extend(bit_input.read_bits_big_endian(subframe.bits_per_sample - subframe.wasted_bits_per_sample), subframe.bits_per_sample)); + decoded.unchecked_append(sign_extend(bit_input.read_bits_big_endian(subframe.bits_per_sample - subframe.wasted_bits_per_sample), subframe.bits_per_sample - subframe.wasted_bits_per_sample)); } decode_residual(decoded, subframe, bit_input);