diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | gst/mpegaudioparse/gstmpegaudioparse.c | 80 |
2 files changed, 37 insertions, 49 deletions
@@ -1,5 +1,11 @@ 2004-01-30 Ronald Bultje <rbultje@ronald.bitfreak.net> + * gst/mpegaudioparse/gstmpegaudioparse.c: + (mp3_type_frame_length_from_header): + Fix header parsing - stolen from ffmpeg (thank you! :) ). + +2004-01-30 Ronald Bultje <rbultje@ronald.bitfreak.net> + * ext/esd/esdsink.c: (gst_esdsink_init): Since we have static pad template caps, we don't need to negotiate; either the core errors out or we know the format. diff --git a/gst/mpegaudioparse/gstmpegaudioparse.c b/gst/mpegaudioparse/gstmpegaudioparse.c index 4914084c..f00e5bcb 100644 --- a/gst/mpegaudioparse/gstmpegaudioparse.c +++ b/gst/mpegaudioparse/gstmpegaudioparse.c @@ -127,61 +127,43 @@ mp3_type_frame_length_from_header (guint32 header, guint *put_layer, guint *put_samplerate) { guint length; - gulong mode, samplerate, bitrate, layer, version, channels; + gulong mode, samplerate, bitrate, layer, channels, padding; + gint lsf, mpg25; - /* we don't need extension, copyright, original or - * emphasis for the frame length */ - header >>= 6; - - /* mode */ - mode = header & 0x3; - header >>= 3; - - /* padding */ - length = header & 0x1; - header >>= 1; - - /* sampling frequency */ - samplerate = header & 0x3; - if (samplerate == 3) - return 0; - header >>= 2; - - /* bitrate index */ - bitrate = header & 0xF; - if (bitrate == 15 || bitrate == 0) - return 0; - - /* ignore error correction, too */ - header >>= 5; - - /* layer */ - layer = 4 - (header & 0x3); - if (layer == 4) - return 0; - header >>= 2; - - /* version */ - version = header & 0x3; - if (version == 1) - return 0; + if (header & (1 << 20)) { + lsf = (header & (1 << 19)) ? 0 : 1; + mpg25 = 0; + } else { + lsf = 1; + mpg25 = 1; + } - /* lookup */ + mode = (header >> 6) & 0x3; channels = (mode == 3) ? 1 : 2; - bitrate = mp3types_bitrates[version == 3 ? 0 : 1][layer - 1][bitrate]; - samplerate = mp3types_freqs[version > 0 ? version - 1 : 0][samplerate]; - - /* calculating */ - if (layer == 1) { - length = ((12000 * bitrate / samplerate) + length) * 4; - } else { - length += ((layer == 3 && version == 0) ? 144000 : 72000) * bitrate / samplerate; + samplerate = (header >> 10) & 0x3; + samplerate = mp3types_freqs[lsf + mpg25][samplerate]; + layer = 4 - ((header >> 17) & 0x3); + bitrate = (header >> 12) & 0xF; + bitrate = mp3types_bitrates[lsf][layer - 1][bitrate] * 1000; + if (bitrate == 0) + return 0; + padding = (header >> 9) & 0x1; + switch (layer) { + case 1: + length = (bitrate * 12) / samplerate + 4 * padding; + break; + case 2: + length = (bitrate * 144) / samplerate + padding; + break; + default: + case 3: + length = (bitrate * 144) / (samplerate << lsf) + padding; + break; } GST_DEBUG ("Calculated mp3 frame length of %u bytes", length); - GST_DEBUG ("samplerate = %lu - bitrate = %lu - layer = %lu - version = %lu" - " - channels = %lu", - samplerate, bitrate, layer, version, channels); + GST_DEBUG ("samplerate = %lu, bitrate = %lu, layer = %lu, channels = %lu", + samplerate, bitrate, layer, channels); if (put_layer) *put_layer = layer; |