From 893669cc101fc0804147f704adff47b343275c69 Mon Sep 17 00:00:00 2001 From: Jens Arnold Date: Sun, 25 Sep 2005 19:07:56 +0000 Subject: Rather obvious simplification of the mpeg frametime fraction calculation. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7562 a1c6a512-1295-4272-9138-f99709370657 --- firmware/mp3data.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) (limited to 'firmware/mp3data.c') diff --git a/firmware/mp3data.c b/firmware/mp3data.c index 519bc60b04..3c9264b7cc 100644 --- a/firmware/mp3data.c +++ b/firmware/mp3data.c @@ -158,23 +158,18 @@ static bool mp3headerinfo(struct mp3info *info, unsigned long header) / info->frequency + info->padding; } - /* Frametime fraction calculation. - This fraction is reduced as far as possible. */ - if (freqindex != 0) { /* 48/32/24/16/12/8 kHz */ - /* integer number of milliseconds, denominator == 1 */ - info->ft_num = 1000 * info->frame_samples / info->frequency; - info->ft_den = 1; + /* Frametime fraction denominator */ + if (freqindex != 0) { /* 48/32/24/16/12/8 kHz */ + info->ft_den = 1; /* integer number of milliseconds */ } - else { /* 44.1/22.05/11.025 kHz */ - if (info->layer == 0) { - info->ft_num = 147000 * 384 / info->frequency; + else { /* 44.1/22.05/11.025 kHz */ + if (info->layer == 0) /* layer 1 */ info->ft_den = 147; - } - else { - info->ft_num = 49000 * info->frame_samples / info->frequency; + else /* layer 2+3 */ info->ft_den = 49; - } } + /* Frametime fraction numerator */ + info->ft_num = 1000 * info->ft_den * info->frame_samples / info->frequency; info->channel_mode = (header & CHANNELMODE_MASK) >> 6; info->mode_extension = (header & MODE_EXT_MASK) >> 4; -- cgit v1.2.3