From 5d437513d0eec0ceddd50f1a60c5abdba5da97b9 Mon Sep 17 00:00:00 2001 From: ayumi Date: Tue, 15 Apr 2025 03:15:16 +0200 Subject: Make WavPack seeking faster MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It turns out that “seeking to a first sample in a not–first block” is actually very common, because Tangara only seeks to exact seconds and the reference encoder tends to size blocks in a way that makes the first sample in a block likely be the sample that the firmware wants to seek to. --- src/codecs/wavpack.cpp | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'src/codecs/wavpack.cpp') diff --git a/src/codecs/wavpack.cpp b/src/codecs/wavpack.cpp index 21865785..7990e4d6 100644 --- a/src/codecs/wavpack.cpp +++ b/src/codecs/wavpack.cpp @@ -73,7 +73,7 @@ auto WavPackDecoder::OpenStream(std::shared_ptr input, uint32_t offset) ); const auto rate = WavpackGetSampleRate(&wavpack_); if (offset && total && input_.get()->CanSeek()) { - const uint32_t want = offset * rate - 1; + const uint32_t want = offset * rate; if (total < want) { ESP_LOGE(kTag, "seeking: offset points beyond the end of the file"); return cpp::fail(Error::kInternalError); @@ -96,7 +96,11 @@ auto WavPackDecoder::OpenStream(std::shared_ptr input, uint32_t offset) } const uint32_t blockIndex = loadLe32(header + 16); const uint32_t blockSamples = loadLe32(header + 20); - if (want >= blockIndex && want <= blockIndex + blockSamples) { + if (want >= blockIndex && want == blockIndex + blockSamples) { + input_->SeekTo(size - 24, IStream::SeekFrom::kCurrentPosition); + target = 0; + break; + } else if (want >= blockIndex && want < blockIndex + blockSamples) { input_->SeekTo(-32, IStream::SeekFrom::kCurrentPosition); target = want - blockIndex; break; -- cgit v1.2.3