From 4704ca52c0da802c89763391768eafa69f8a2f6e Mon Sep 17 00:00:00 2001
From: Chris Smowton <cs448@cam.ac.uk>
Date: Mon, 22 Sep 2014 00:11:16 +0100
Subject: [PATCH] Add M4A import support using MP4V2 and faad.

---
 configure.ac           |  23 ++++++++-
 lib/rdaudioconvert.cpp |  74 ++++++++++++++++++++++++++++
 lib/rdaudioconvert.h   |   2 +
 lib/rdwavefile.cpp     | 107 +++++++++++++++++++++++++++++++++++++++++
 lib/rdwavefile.h       |   4 +-
 5 files changed, 208 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 04b39930..5c20fb9c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -78,6 +78,8 @@ AC_ARG_ENABLE(lame,[  --disable-lame          disable MPEG Layer 3 encode suppor
 		      [LAME_DISABLED=yes],[])
 AC_ARG_ENABLE(flac,[  --disable-flac          disable FLAC encode/decode support],
 		      [FLAC_DISABLED=yes],[])
+AC_ARG_ENABLE(mp4v2,[ --disable-mp4           disable M4A decode support],
+		      [MP4V2_DISABLED=yes],[])
 
 #
 # Check for Qt
@@ -206,10 +208,24 @@ if test -z $FLAC_DISABLED ; then
   AC_CHECK_LIB(FLAC,FLAC__metadata_get_tags,[FLAC_METADATA_FOUND=yes],[])
 fi
 
+#
+# Check for MP4V2
+#
+if test -z $MP4V2_DISABLED ; then
+  AC_CHECK_HEADER(mp4v2/mp4v2.h,[MP4V2_HEADER_FOUND=yes],[])
+  if test $MP4V2_HEADER_FOUND ; then
+    AC_CHECK_LIB(mp4v2,MP4Read,[MP4V2_FOUND=yes],[])
+  fi
+  if test $MP4V2_FOUND ; then
+    MP4V2_LIBS="-lmp4v2"
+    AC_DEFINE(HAVE_MP4V2)
+  fi
+fi
+
 #
 # Set Hard Library Dependencies
 #
-AC_SUBST(LIB_RDLIBS,"-lm -lpthread -lqui -lrd -lcurl -lid3 $FLAC_LIBS -lsndfile -lsamplerate -lcdda_interface -lcdda_paranoia -lcrypt -ldl -lpam -lSoundTouch")
+AC_SUBST(LIB_RDLIBS,"-lm -lpthread -lqui -lrd -lcurl -lid3 $FLAC_LIBS $MP4V2_LIBS -lsndfile -lsamplerate -lcdda_interface -lcdda_paranoia -lcrypt -ldl -lpam -lSoundTouch")
 
 #
 # Setup MPEG Dependencies
@@ -531,6 +547,11 @@ AC_MSG_NOTICE("|       OggVorbis Encoding/Decoding Support ... No    |")
 else
 AC_MSG_NOTICE("|       OggVorbis Encoding/Decoding Support ... Yes   |")
 fi
+if test -z $MP4V2_FOUND ; then
+AC_MSG_NOTICE("|                      M4A Decoding Support ... No    |")
+else
+AC_MSG_NOTICE("|                      M4A Decoding Support ... Yes   |")
+fi
 AC_MSG_NOTICE("|                                                     |")
 AC_MSG_NOTICE("| Optional Components:                                |")
 if test -z $USING_PAM ; then
diff --git a/lib/rdaudioconvert.cpp b/lib/rdaudioconvert.cpp
index a9767ca2..edd9bbbb 100644
--- a/lib/rdaudioconvert.cpp
+++ b/lib/rdaudioconvert.cpp
@@ -23,11 +23,13 @@
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <math.h>
 #include <dlfcn.h>
 #include <errno.h>
+#include <unistd.h>
 
 #include <sndfile.h>
 #include <samplerate.h>
@@ -307,6 +309,11 @@ RDAudioConvert::ErrorCode RDAudioConvert::Stage1Convert(const QString &srcfile,
       delete wave;
       return err;
 
+    case RDWaveFile::M4A:
+      err=Stage1M4A(dstfile,wave);
+      delete wave;
+      return err;
+
     case RDWaveFile::Aiff:
     case RDWaveFile::Unknown:
       break;
@@ -673,6 +680,73 @@ RDAudioConvert::ErrorCode RDAudioConvert::Stage1Mpeg(const QString &dstfile,
 #endif  // HAVE_MAD
 }
 
+RDAudioConvert::ErrorCode RDAudioConvert::Stage1M4A(const QString &dstfile,
+						    RDWaveFile *wave) {
+
+  const char* args[7];
+  int childstatus = 0; 
+ 
+  pid_t child = fork();
+
+  QString tmpname = dstfile + ".m4a_temp.wav";
+ 
+  if(child == 0) {
+
+    freopen("/dev/null", "w", stdout);
+    freopen("/dev/null", "w", stderr);
+
+    args[0] = "faad";
+    args[1] = wave->getName();
+    args[2] = "-o";
+    args[3] = tmpname;
+    args[4] = "-b";
+    args[5] = "4"; // Emit a Float32 format wave file, like the other stage 1s.
+    args[6] = 0;
+    execvp("faad", (char* const*)args);
+    exit(109);
+
+  }
+  else {
+
+    waitpid(child, &childstatus, 0);
+
+    // Killed by a signal (e.g. OOM?)
+    if(!WIFEXITED(childstatus)) {
+      unlink(tmpname);
+      return RDAudioConvert::ErrorInternal;
+    }
+
+    // Returned 109, probably because we could't find faad?
+    if(WEXITSTATUS(childstatus) == 109)
+      return RDAudioConvert::ErrorFormatNotSupported;
+
+    // Two elements are missing: 
+    // 1. need to measure the peak amplitude;
+    // 2. need to trim if a subrange was requested.
+    // For now just use the sndfile import path to accomplish both tasks.
+
+    {
+
+      SF_INFO sf_src_info;
+      SNDFILE* sf_src;
+
+      memset(&sf_src_info, 0, sizeof(sf_src_info));
+      // If this fails it is likely because faad could not decode.
+      if((sf_src = sf_open(tmpname, SFM_READ, &sf_src_info)) == NULL)
+	return RDAudioConvert::ErrorFormatError;
+
+      RDAudioConvert::ErrorCode err = Stage1SndFile(dstfile, sf_src, &sf_src_info);
+
+      sf_close(sf_src);
+      unlink(tmpname);
+
+      return err;
+
+    }
+
+  }
+
+}
 
 RDAudioConvert::ErrorCode RDAudioConvert::Stage1SndFile(const QString &dstfile,
 							SNDFILE *sf_src,
diff --git a/lib/rdaudioconvert.h b/lib/rdaudioconvert.h
index 3b833c9a..14eeb976 100644
--- a/lib/rdaudioconvert.h
+++ b/lib/rdaudioconvert.h
@@ -70,6 +70,8 @@ class RDAudioConvert : public QObject
 					 RDWaveFile *wave);
   RDAudioConvert::ErrorCode Stage1Mpeg(const QString &dstfile,
 				       RDWaveFile *wave);
+  RDAudioConvert::ErrorCode Stage1M4A(const QString &dstfile,
+				      RDWaveFile *wave);
   RDAudioConvert::ErrorCode Stage1SndFile(const QString &dstfile,
 					  SNDFILE *sf_src,
 					  SF_INFO *sf_src_info);
diff --git a/lib/rdwavefile.cpp b/lib/rdwavefile.cpp
index c09f9985..5c2408de 100644
--- a/lib/rdwavefile.cpp
+++ b/lib/rdwavefile.cpp
@@ -48,6 +48,10 @@
 #include <rdwavefile.h>
 #include <rdconf.h>
 
+#ifdef HAVE_MP4V2
+#include <mp4v2/mp4v2.h>
+#endif
+
 RDWaveFile::RDWaveFile(QString file_name)
 {
   // 
@@ -322,6 +326,94 @@ bool RDWaveFile::openWave(RDWaveData *data)
     ReadId3Metadata();
     break;
 
+  case RDWaveFile::M4A:
+    {
+#ifdef HAVE_MP4V2   
+
+      format_tag=WAVE_FORMAT_M4A;
+
+      MP4FileHandle f = MP4Read(getName());
+      if(f == MP4_INVALID_FILE_HANDLE)
+	return false;
+
+      // Find an audio track, and populate sample rate, bits/sample etc.
+      uint32_t nTracks = MP4GetNumberOfTracks(f);
+
+      MP4TrackId audioTrack = MP4_INVALID_TRACK_ID;
+      for(uint32_t trackIndex = 0; trackIndex < nTracks && audioTrack == MP4_INVALID_TRACK_ID; ++trackIndex) {
+
+	MP4TrackId thisTrack = MP4FindTrackId(f, trackIndex);
+	const char* trackType = MP4GetTrackType(f, thisTrack);
+	if(trackType && !strcmp(trackType, MP4_AUDIO_TRACK_TYPE)) {
+   
+	  const char* dataName = MP4GetTrackMediaDataName(f, thisTrack);
+	  // The M4A format is only currently useful for AAC in an M4A container:
+	  if(dataName && 
+	     (!strcasecmp(dataName, "mp4a")) && 
+	     MP4GetTrackEsdsObjectTypeId(f, thisTrack) == MP4_MPEG4_AUDIO_TYPE) {
+
+	    audioTrack = thisTrack;
+
+	  }
+
+	}
+
+      }
+
+      if(audioTrack == MP4_INVALID_TRACK_ID) {
+	MP4Close(f);
+	return false;
+      }
+
+      // Found audio track. Get audio data:
+      avg_bytes_per_sec = MP4GetTrackBitRate(f, audioTrack);
+      channels = MP4GetTrackAudioChannels(f, audioTrack);
+
+      MP4Duration trackDuration = MP4GetTrackDuration(f, audioTrack);
+      ext_time_length = (unsigned)MP4ConvertFromTrackDuration(f, audioTrack, trackDuration, 
+							      MP4_MSECS_TIME_SCALE);
+      time_length = ext_time_length / 1000;
+      samples_per_sec = MP4GetTrackTimeScale(f, audioTrack);
+      bits_per_sample = 16;
+      data_start = 0;
+      sample_length = MP4GetTrackNumberOfSamples(f, audioTrack);
+      data_length = sample_length * 2 * channels;
+      data_chunk = true;
+      format_chunk = true;
+      wave_type = RDWaveFile::M4A;
+
+      // Now extract metadata (title, artist, etc)
+
+      if(wave_data) {
+
+	const MP4Tags* tags = MP4TagsAlloc();
+	MP4TagsFetch(tags, f);
+	
+	wave_data->setMetadataFound(true);
+	
+	if(tags->name)
+	  wave_data->setTitle(tags->name);
+	if(tags->artist)
+	  wave_data->setArtist(tags->artist);
+	if(tags->composer)
+	  wave_data->setComposer(tags->composer);
+	if(tags->album)
+	  wave_data->setAlbum(tags->album);
+
+	MP4TagsFree(tags);
+
+      }
+
+      MP4Close(f);
+
+      return true;
+
+#else
+      return false;
+#endif
+      break;
+    }
+
   case RDWaveFile::Ogg:
 #ifdef HAVE_VORBIS
     format_tag=WAVE_FORMAT_VORBIS;
@@ -2020,6 +2112,9 @@ RDWaveFile::Type RDWaveFile::GetType(int fd)
   if(IsOgg(fd)) {
     return RDWaveFile::Ogg;
   }
+  if(IsM4A(fd)) {
+    return RDWaveFile::M4A;
+  }
   if(IsMpeg(fd)) {
     return RDWaveFile::Mpeg;
   }
@@ -2211,6 +2306,18 @@ bool RDWaveFile::IsAiff(int fd)
   return true;
 }
 
+bool RDWaveFile::IsM4A(int fd)
+{
+#ifdef HAVE_MP4V2
+  MP4FileHandle f = MP4Read(getName());
+  bool ret = f != MP4_INVALID_FILE_HANDLE;
+  if(ret)
+    MP4Close(f);
+  return ret;
+#else
+  return false;
+#endif
+}
 
 off_t RDWaveFile::FindChunk(int fd,const char *chunk_name,unsigned *chunk_size,
 			    bool big_end)
diff --git a/lib/rdwavefile.h b/lib/rdwavefile.h
index fbe4cfc1..c4a632fc 100644
--- a/lib/rdwavefile.h
+++ b/lib/rdwavefile.h
@@ -116,7 +116,7 @@ class RDWaveFile
   enum Format {Pcm8=0,Pcm16=1,Float32=2,MpegL1=3,MpegL2=4,MpegL3=5,
 	       DolbyAc2=6,DolbyAc3=7,Vorbis=8};
   enum Type {Unknown=0,Wave=1,Mpeg=2,Ogg=3,Atx=4,Tmc=5,Flac=6,Ambos=7,
-	     Aiff=8};
+	     Aiff=8,M4A=9};
   enum MpegID {NonMpeg=0,Mpeg1=1,Mpeg2=2};
 
   /**
@@ -1046,6 +1046,7 @@ class RDWaveFile
    bool IsTmc(int fd);
    bool IsFlac(int fd);
    bool IsAiff(int fd);
+   bool IsM4A(int fd);
    off_t FindChunk(int fd,const char *chunk_name,unsigned *chunk_size,
 		   bool big_end=false);
    bool GetChunk(int fd,const char *chunk_name,unsigned *chunk_size,
@@ -1378,6 +1379,7 @@ class RDWaveFile
  */
 #define WAVE_FORMAT_VORBIS 0xFFFF
 #define WAVE_FORMAT_FLAC 0xFFFE
+#define WAVE_FORMAT_M4A 0xFFFD
 
 /*
  * Proprietary Format Categories