Add an mp3 decoder using libmpg123

Does not currently handle direct file sources

FindMPG123.cmake

@@ -0,0 +1,28 @@
+# - Find mpg123
+# Find the native mpg123 includes and library
+#
+#  MPG123_INCLUDE_DIR - where to find mpg123.h
+#  MPG123_LIBRARIES   - List of libraries when using mpg123.
+#  MPG123_FOUND       - True if mpg123 found.
+
+IF(MPG123_INCLUDE_DIR AND MPG123_LIBRARIES)
+  # Already in cache, be silent
+  SET(MPG123_FIND_QUIETLY TRUE)
+ENDIF(MPG123_INCLUDE_DIR AND MPG123_LIBRARIES)
+
+FIND_PATH(MPG123_INCLUDE_DIR mpg123.h
+          PATHS "${MPG123_DIR}"
+          PATH_SUFFIXES include
+          )
+
+FIND_LIBRARY(MPG123_LIBRARIES NAMES mpg123 mpg123-0
+             PATHS "${MPG123_DIR}"
+             PATH_SUFFIXES lib
+             )
+
+MARK_AS_ADVANCED(MPG123_LIBRARIES MPG123_INCLUDE_DIR)
+
+# handle the QUIETLY and REQUIRED arguments and set MPG123_FOUND to TRUE if
+# all listed variables are TRUE
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(MPG123 DEFAULT_MSG MPG123_LIBRARIES MPG123_INCLUDE_DIR)

src/CMakeLists.txt

@@ -299,6 +299,10 @@ endif( NO_OPENAL )
 
 find_package( SndFile )
 
+# Search for libmpg123
+
+find_package( MPG123 )
+
 # Search for FluidSynth
 
 find_package( FluidSynth )
@@ -553,7 +557,10 @@ if( SNDFILE_FOUND )
     set( ZDOOM_LIBS ${ZDOOM_LIBS} "${SNDFILE_LIBRARIES}" )
     include_directories( "${SNDFILE_INCLUDE_DIRS}" )
 endif( SNDFILE_FOUND )
-
+if( MPG123_FOUND )
+    set( ZDOOM_LIBS ${ZDOOM_LIBS} "${MPG123_LIBRARIES}" )
+    include_directories( "${MPG123_INCLUDE_DIR}" )
+endif( MPG123_FOUND )
 if( NOT DYN_FLUIDSYNTH)
 	if( FLUIDSYNTH_FOUND )
 		set( ZDOOM_LIBS ${ZDOOM_LIBS} "${FLUIDSYNTH_LIBRARIES}" )
@@ -671,6 +678,9 @@ endif( SSE_MATTERS )
 if( SNDFILE_FOUND )
     add_definitions( -DHAVE_SNDFILE )
 endif( SNDFILE_FOUND )
+if( MPG123_FOUND )
+    add_definitions( -DHAVE_MPG123 )
+endif( MPG123_FOUND )
 if( DYN_FLUIDSYNTH )
 	add_definitions( -DHAVE_FLUIDSYNTH -DDYN_FLUIDSYNTH )
 elseif( FLUIDSYNTH_FOUND )
@@ -1034,6 +1044,7 @@ add_executable( zdoom WIN32
 	resourcefiles/file_directory.cpp
 	resourcefiles/resourcefile.cpp
 	sfmt/SFMT.cpp
+	sound/audio_mpg123_decoder.cpp
 	sound/audio_sndfile_decoder.cpp
 	sound/fmodsound.cpp
 	sound/i_music.cpp

src/sound/audio_mpg123_decoder.cpp

@@ -0,0 +1,167 @@
+#include "i_soundinternal.h"
+
+#ifdef HAVE_MPG123
+static bool inited = false;
+
+
+off_t MPG123Decoder::mem_lseek(void *handle, off_t offset, int whence)
+{
+    MPG123Decoder *self = reinterpret_cast<MPG123Decoder*>(handle);
+
+    switch(whence)
+    {
+        case SEEK_SET:
+            if(offset < 0 || offset > (off_t)self->MemLength)
+                return -1;
+            self->MemPos = offset;
+            break;
+
+        case SEEK_CUR:
+            if((offset > 0 && (off_t)(self->MemLength-self->MemPos) < offset) ||
+               (offset < 0 && (off_t)self->MemPos < -offset))
+                return -1;
+            self->MemPos += offset;
+            break;
+
+        case SEEK_END:
+            if(offset > 0 || -offset > (off_t)self->MemLength)
+                return -1;
+            self->MemPos = self->MemLength + offset;
+            break;
+
+        default:
+            return -1;
+    }
+
+    return self->MemPos;
+}
+
+ssize_t MPG123Decoder::mem_read(void *handle, void *buffer, size_t bytes)
+{
+    MPG123Decoder *self = reinterpret_cast<MPG123Decoder*>(handle);
+
+    if(bytes > self->MemLength-self->MemPos)
+        bytes = self->MemLength-self->MemPos;
+
+    memcpy(buffer, self->MemData+self->MemPos, bytes);
+    self->MemPos += bytes;
+
+    return bytes;
+}
+
+
+MPG123Decoder::~MPG123Decoder()
+{
+    if(MPG123)
+    {
+        mpg123_close(MPG123);
+        mpg123_delete(MPG123);
+        MPG123 = 0;
+    }
+}
+
+bool MPG123Decoder::open(const char *data, size_t length)
+{
+    if(!inited)
+    {
+        if(mpg123_init() != MPG123_OK)
+            return false;
+        inited = true;
+    }
+
+    MemData = data;
+    MemPos = 0;
+    MemLength = length;
+
+    MPG123 = mpg123_new(NULL, NULL);
+    if(mpg123_replace_reader_handle(MPG123, mem_read, mem_lseek, NULL) == MPG123_OK &&
+       mpg123_open_handle(MPG123, this) == MPG123_OK)
+    {
+        int enc, channels;
+        long srate;
+
+        if(mpg123_getformat(MPG123, &srate, &channels, &enc) == MPG123_OK)
+        {
+            if((channels == 1 || channels == 2) && srate > 0 &&
+               mpg123_format_none(MPG123) == MPG123_OK &&
+               mpg123_format(MPG123, srate, channels, MPG123_ENC_SIGNED_16) == MPG123_OK)
+            {
+                // All OK
+                Done = false;
+                return true;
+            }
+        }
+        mpg123_close(MPG123);
+    }
+    mpg123_delete(MPG123);
+    MPG123 = 0;
+
+    return false;
+}
+
+void MPG123Decoder::getInfo(int *samplerate, ChannelConfig *chans, SampleType *type)
+{
+    int enc = 0, channels = 0;
+    long srate = 0;
+
+    mpg123_getformat(MPG123, &srate, &channels, &enc);
+
+    *samplerate = srate;
+
+    if(channels == 2)
+        *chans = ChannelConfig_Stereo;
+    else
+        *chans = ChannelConfig_Mono;
+
+    *type = SampleType_Int16;
+}
+
+size_t MPG123Decoder::read(char *buffer, size_t bytes)
+{
+    size_t amt = 0;
+    while(!Done && bytes > 0)
+    {
+        size_t got = 0;
+        int ret = mpg123_read(MPG123, (unsigned char*)buffer, bytes, &got);
+
+        bytes -= got;
+        buffer += got;
+        amt += got;
+
+        if(ret == MPG123_NEW_FORMAT || ret == MPG123_DONE || got == 0)
+        {
+            Done = true;
+            break;
+        }
+    }
+    return amt;
+}
+
+bool MPG123Decoder::open(const char *fname, size_t offset, size_t length)
+{
+    return false;
+}
+
+bool MPG123Decoder::seek(size_t ms_offset)
+{
+    int enc, channels;
+    long srate;
+
+    if(mpg123_getformat(MPG123, &srate, &channels, &enc) == MPG123_OK)
+    {
+        size_t smp_offset = (size_t)((double)ms_offset / 1000. * srate);
+        if(mpg123_seek(MPG123, smp_offset, SEEK_SET) >= 0)
+        {
+            Done = false;
+            return true;
+        }
+    }
+    return false;
+}
+
+size_t MPG123Decoder::getSampleOffset()
+{
+    return mpg123_tell(MPG123);
+}
+
+#endif

src/sound/i_sound.cpp

@@ -524,12 +524,64 @@ SoundHandle SoundRenderer::LoadSoundVoc(BYTE *sfxdata, int length)
 SoundDecoder *SoundRenderer::CreateDecoder(const BYTE *sfxdata, int length)
 {
     SoundDecoder *decoder = NULL;
-#ifdef HAVE_SNDFILE
+#ifdef HAVE_MPG123
-    decoder = new SndFileDecoder;
+    int mpg_start = -1;
-    if(!decoder->open((const char*)sfxdata, length))
+    int mpg_len = -1;
+
+    // Check for an ID3 tag to identify an mp3 (and skip the tag)
+    if(length > 10 && memcmp(sfxdata, "ID3", 3) == 0 &&
+       sfxdata[3] <= 4 && sfxdata[4] != 0xff &&
+       (sfxdata[5]&0x0f) == 0 && (sfxdata[6]&0x80) == 0 &&
+       (sfxdata[7]&0x80) == 0 && (sfxdata[8]&0x80) == 0 &&
+       (sfxdata[9]&0x80) == 0)
     {
-        delete decoder;
+        // ID3v2
-        decoder = NULL;
+        mpg_start = (sfxdata[6]<<21) | (sfxdata[7]<<14) |
+                    (sfxdata[8]<< 7) | (sfxdata[9]    );
+        mpg_start += ((sfxdata[5]&0x10) ? 20 : 10);
+        mpg_len = length - mpg_start;
+    }
+    else if(length > 128 && memcmp(sfxdata+length-128, "TAG", 3) == 0)
+    {
+        // ID3v1
+        mpg_start = 0;
+        mpg_len = length - 128;
+    }
+    else if(length > 3)
+    {
+        // No ID3 tag. Check for a frame header
+        if((sfxdata[0] == 0xff && sfxdata[1]>>1 == 0x7d) || // MPEG-1
+           (sfxdata[0] == 0xff && sfxdata[1]>>1 == 0x79))   // MPEG-2
+        {
+            int brate_idx = (sfxdata[2]>>4) & 0x0f;
+            int srate_idx = (sfxdata[2]>>2) & 0x03;
+            if(brate_idx != 0 && brate_idx != 15 && srate_idx != 3)
+            {
+                mpg_start = 0;
+                mpg_len = length;
+            }
+        }
+    }
+
+    if(mpg_start >= 0 && mpg_len > 0 && mpg_start < length && mpg_len <= length-mpg_start)
+    {
+        decoder = new MPG123Decoder;
+        if(!decoder->open((const char*)sfxdata+mpg_start, mpg_len))
+        {
+            delete decoder;
+            decoder = NULL;
+        }
+    }
+#endif
+#ifdef HAVE_SNDFILE
+    if(!decoder)
+    {
+        decoder = new SndFileDecoder;
+        if(!decoder->open((const char*)sfxdata, length))
+        {
+            delete decoder;
+            decoder = NULL;
+        }
     }
 #endif
     return decoder;

src/sound/i_soundinternal.h

@@ -139,6 +139,38 @@ private:
     SoundDecoder& operator=(const SoundDecoder &rhs);
 };
 
+#ifdef HAVE_MPG123
+#include "mpg123.h"
+struct MPG123Decoder : public SoundDecoder
+{
+    virtual void getInfo(int *samplerate, ChannelConfig *chans, SampleType *type);
+
+    virtual size_t read(char *buffer, size_t bytes);
+    virtual bool seek(size_t ms_offset);
+    virtual size_t getSampleOffset();
+
+    MPG123Decoder() : MPG123(0) { }
+    virtual ~MPG123Decoder();
+
+protected:
+    virtual bool open(const char *data, size_t length);
+    virtual bool open(const char *fname, size_t offset, size_t length);
+
+private:
+    mpg123_handle *MPG123;
+    bool Done;
+
+    const char *MemData;
+    size_t MemLength;
+    size_t MemPos;
+    static off_t mem_lseek(void *handle, off_t offset, int whence);
+    static ssize_t mem_read(void *handle, void *buffer, size_t bytes);
+
+    // Make non-copyable
+    MPG123Decoder(const MPG123Decoder &rhs);
+    MPG123Decoder& operator=(const MPG123Decoder &rhs);
+};
+#endif
 #ifdef HAVE_SNDFILE
 #include "sndfile.h"
 struct SndFileDecoder : public SoundDecoder