ref: cbdab0ba1bf3e009222e3038bcac0efc1de627f8
parent: c42b41dc0d8e3c120fbf950180def271ac15bb2e
author: cbagwell <cbagwell>
date: Wed Jan 3 13:33:51 EST 2007
Adding seek support for GSM WAV files
--- a/ChangeLog
+++ b/ChangeLog
@@ -85,6 +85,7 @@
o Improved multi-channel file reading; fixes [1599990]. (robs)
o New options for specifying endianness (and separate option for
bit reversal) [FR# 1621702]. (robs)
+ o Add seek support for GSM data in WAV files. Rafal Maszkowski
sox-12.18.2
-----------
--- a/src/wav.c
+++ b/src/wav.c
@@ -1691,9 +1691,32 @@
{case WAVE_FORMAT_IMA_ADPCM:
case WAVE_FORMAT_ADPCM:
- case WAVE_FORMAT_GSM610:
st_fail_errno(ft,ST_ENOTSUP,"Only PCM Supported");
break;
+
+ case WAVE_FORMAT_GSM610:
+ { + st_size_t gsmoff;
+
+ /* rounding bytes to blockAlign so that we
+ * don't have to decode partial block. */
+ gsmoff = offset * wav->blockAlign / wav->samplesPerBlock +
+ wav->blockAlign * ft->signal.channels / 2;
+ gsmoff -= gsmoff % (wav->blockAlign * ft->signal.channels);
+
+ ft->st_errno = st_seeki(ft, gsmoff + wav->dataStart, SEEK_SET);
+ if (ft->st_errno != ST_SUCCESS)
+ return ST_EOF;
+
+ /* offset is in samples */
+ new_offset = offset;
+ alignment = offset % wav->samplesPerBlock;
+ if (alignment != 0)
+ new_offset += (wav->samplesPerBlock - alignment);
+ wav->numSamples = ft->length - (new_offset / ft->signal.channels);
+ }
+ break;
+
default:
new_offset = offset * ft->signal.size;
/* Make sure request aligns to a channel block (ie left+right) */