From a091b9684d877827287a51259edce3140112667a Mon Sep 17 00:00:00 2001 From: Kostya Shishkov Date: Mon, 22 Nov 2021 18:44:32 +0100 Subject: [PATCH] mpegaudio: get duration from Xing/LAME information if available --- nihav-mpeg/src/codecs/mpegaudio/mod.rs | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/nihav-mpeg/src/codecs/mpegaudio/mod.rs b/nihav-mpeg/src/codecs/mpegaudio/mod.rs index 0ca85f5..187a695 100644 --- a/nihav-mpeg/src/codecs/mpegaudio/mod.rs +++ b/nihav-mpeg/src/codecs/mpegaudio/mod.rs @@ -1,4 +1,5 @@ use nihav_core::codecs::*; +use nihav_core::io::byteio::read_u32be; use nihav_core::io::bitreader::*; use nihav_codec_support::dsp::qmf::QMF; @@ -361,9 +362,25 @@ impl NAPacketiser for MPAPacketiser { self.hdr = Some(hdr); } let hdr = self.hdr.unwrap(); + let mut duration = 0; + if hdr.layer == 2 { // check for Xing/LAME info + let mpeg1 = hdr.srate >= 32000; + let offset = match (mpeg1, hdr.channels) { + (true, 1) => 24, + (true, _) => 36, + (false, 1) => 13, + (false, _) => 21, + }; + if self.buf.len() >= offset + 12 && (&self.buf[offset..][..4] == b"Xing" || &self.buf[offset..][..4] == b"Info") { + let flags = read_u32be(&self.buf[offset + 4..]).unwrap_or(0); + if (flags & 1) != 0 { + duration = u64::from(read_u32be(&self.buf[offset + 8..]).unwrap_or(0)); + } + } + } let ainfo = NAAudioInfo::new(hdr.srate, hdr.channels, SND_F32P_FORMAT, hdr.nsamples); let info = NACodecInfo::new("mp3", NACodecTypeInfo::Audio(ainfo), None); - Ok(NAStream::new(StreamType::Audio, id, info, hdr.nsamples as u32, hdr.srate, 0).into_ref()) + Ok(NAStream::new(StreamType::Audio, id, info, hdr.nsamples as u32, hdr.srate, duration).into_ref()) } fn skip_junk(&mut self) -> DecoderResult { if self.buf.len() <= 2 { -- 2.30.2