Make WAV file reading correct so that optional chunks can be tolerated

The WAV file format allows for optional header content, allow for this
in preparation for adding some metadata to WSJT-X recorded WAV files.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6335 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

CMakeLists.txt

@@ -368,6 +368,7 @@ set (wsjt_FSRCS
   lib/polyfit.f90
   lib/prog_args.f90
   lib/ps4.f90
+  lib/readwav.f90
   lib/rectify_msk.f90
   lib/savec2.f90
   lib/sec_midn.f90

getfile.cpp

@@ -1,6 +1,8 @@
 #include "getfile.h"
 #include <QDir>
 #include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
 #include <math.h>
 
 #ifdef WIN32
@@ -60,10 +62,41 @@ void getfile(QString fname, int ntrperiod)
   memset(dec_data.d2,0,2*npts);
 
   if(fp != NULL) {
+    struct
+    {
+      char id[4];
+      uint32_t size;
+    } desc;
+    char type[4];
+    struct
+    {
+      uint16_t nfmt2;
+      uint16_t nchan2;
+      uint32_t nsamrate;
+      uint32_t nbytesec;
+      uint16_t nbytesam2;
+      uint16_t nbitsam2;
+    } fmt;
+
+    // read header
+    fread(&desc, 1, sizeof desc, fp); // RIFF
+    fread(type, 1, sizeof type, fp);  // WAVE
+    do
+      {
+        fread(&desc, 1, sizeof desc, fp); // WAVE component
+        if (!memcmp(desc.id,"fmt ",4)) {
+          fpos_t pos;
+          fgetpos(fp,&pos);
+          fread(&fmt,1,sizeof fmt,fp);
+          fsetpos(fp,&pos);
+        }
+        if (!memcmp(desc.id,"data",sizeof desc.id)) break;
+      } while (!fseek(fp,(desc.size + 1) / 2 * 2,SEEK_CUR));
+    
 // Read (and ignore) a 44-byte WAV header; then read data
-    int n=fread(&hdr,1,44,fp);
-    n=fread(dec_data.d2,2,npts,fp);
-    if(hdr.nsamrate==11025) wav12_(dec_data.d2,dec_data.d2,&n,&hdr.nbitsam2);
+//    int n=fread(&hdr,1,44,fp);
+    int n=fread(dec_data.d2,2,npts,fp);
+    if(hdr.nsamrate==11025) wav12_(dec_data.d2,dec_data.d2,&n,(short*)&fmt.nbitsam2);
     fclose(fp);
     dec_data.params.newdat=1;
     dec_data.params.kin=n;

lib/jt65.f90

@@ -6,17 +6,17 @@ program jt65
   use timer_module, only: timer
   use timer_impl, only: init_timer
   use jt65_test
+  use readwav
 
   character c
   logical :: display_help=.false.,nrobust=.false.
-  integer*4 ihdr(11)
+  type(wav_header) :: wav
   integer*2 id2(NZMAX)
   real*4 dd(NZMAX)
   character*80 infile
   character(len=500) optarg
   character*12 mycall,hiscall
   character*6 hisgrid
-  equivalence (lenfile,ihdr(2))
   type (option) :: long_options(10) = [ &
        option ('aggressive',.true.,'a','aggressiveness [0-10], default AGGR=0','AGGR'), &
        option ('freq',.true.,'f','signal frequency, default FREQ=1270','FREQ'),         &
@@ -95,21 +95,17 @@ program jt65
      minsync=0
      call get_command_argument(ifile,optarg,narglen)
      infile=optarg(:narglen)
-     open(10,file=infile,access='stream',status='old',err=998)
      call timer('read    ',0)
-     read(10) ihdr
+     call wav%read (infile)
      i1=index(infile,'.wav')
      if( i1 .eq. 0 ) i1=index(infile,'.WAV')
      read(infile(i1-4:i1-1),*,err=998) nutc
      npts=52*12000
-     read(10) id2(1:npts)
+     read(unit=wav%lun) id2(1:npts)
+     close(unit=wav%lun)
      call timer('read    ',1)
      dd(1:npts)=id2(1:npts)
      dd(npts+1:)=0.
-
-     !     open(56,file='subtracted.wav',access='stream',status='unknown')
-     !     write(56) ihdr(1:11)
-
      call test(dd,nutc,nfa,nfb,nfqso,ntol,nsubmode, &
           n2pass,nrobust,ntrials,naggressive, &
           mycall,hiscall,hisgrid,nexp_decoded)

lib/jt9.f90

@@ -9,11 +9,12 @@ program jt9
   use FFTW3
   use timer_module, only: timer
   use timer_impl, only: init_timer, fini_timer
+  use readwav
 
   include 'jt9com.f90'
 
   integer(C_INT) iret
-  integer*4 ihdr(11)
+  type(wav_header) wav
   real*4 s(NSMAX)
   character c
   character(len=500) optarg, infile
@@ -172,10 +173,8 @@ program jt9
   do iarg = offset + 1, offset + remain
      call get_command_argument (iarg, optarg, arglen)
      infile = optarg(:arglen)
-     open(10,file=infile,access='stream',status='old',err=998)
-     read(10) ihdr
-     nfsample=ihdr(7)
-     nutc=ihdr(1)                           !Silence compiler warning
+     call wav%read (infile)
+     nfsample=wav%audio_format%sample_rate
      i1=index(infile,'.wav')
      if(i1.lt.1) i1=index(infile,'.WAV')
      if(infile(i1-5:i1-5).eq.'_') then
@@ -218,7 +217,7 @@ program jt9
      do iblk=1,npts/kstep
         k=iblk*kstep
         call timer('read_wav',0)
-        read(10,end=3) shared_data%id2(k-kstep+1:k)
+        read(unit=wav%lun,end=3) shared_data%id2(k-kstep+1:k)
         go to 4
 3       call timer('read_wav',1)
         print*,'EOF on input file ',infile
@@ -239,7 +238,7 @@ program jt9
            if(nhsym.ge.181) exit
         endif
      enddo
-     close(10)
+     close(unit=wav%lun)
      shared_data%params%nutc=nutc
      shared_data%params%ndiskdat=.true.
      shared_data%params%ntr=60
@@ -290,10 +289,6 @@ program jt9
 
   call timer('jt9     ',1)
   call timer('jt9     ',101)
-  go to 999
-
-998 print*,'Cannot open file:'
-  print*,infile
 
 999 continue
   ! Output decoder statistics

lib/readwav.f90

@@ -0,0 +1,51 @@
+module readwav
+  implicit none
+
+  type format_chunk
+     integer*2 audio_format
+     integer*2 num_channels
+     integer sample_rate
+     integer byte_rate
+     integer*2 block_align
+     integer*2 bits_per_sample
+  end type format_chunk
+  
+  type, public :: wav_header
+     integer :: lun
+     type(format_chunk) :: audio_format
+   contains
+     procedure :: read
+  end type wav_header
+
+  private
+contains
+  subroutine read (this, filename)
+    implicit none
+
+    type riff_descriptor
+       character(len=4) :: id
+       integer :: size
+    end type riff_descriptor
+
+    class(wav_header), intent(inout) :: this
+    character(len=*), intent(in) :: filename
+
+    integer :: filepos
+    type(riff_descriptor) :: desc
+    character(len=4) :: riff_type
+
+    open (newunit=this%lun, file=filename, access='stream', form='unformatted', status='old')
+    read (unit=this%lun) desc,riff_type
+    inquire (unit=this%lun, pos=filepos)
+    do
+       read (unit=this%lun, pos=filepos) desc
+       inquire (unit=this%lun, pos=filepos)
+       if (desc%id .eq. 'fmt ') then
+          read (unit=this%lun) this%audio_format
+       else if (desc%id .eq. 'data') then
+          exit
+       end if
+       filepos = filepos + (desc%size + 1) / 2 * 2 ! pad to even alignment
+    end do
+  end subroutine read
+end module readwav