Added MPEG library

CMakeLists.txt

@@ -152,6 +152,7 @@ set(libHeaders
   ${SOURCE_DIR}/lib/mp4_generic.h
   ${SOURCE_DIR}/lib/mp4.h
   ${SOURCE_DIR}/lib/mp4_ms.h
+  ${SOURCE_DIR}/lib/mpeg.h
   ${SOURCE_DIR}/lib/nal.h
   ${SOURCE_DIR}/lib/ogg.h
   ${SOURCE_DIR}/lib/procs.h
@@ -200,6 +201,7 @@ set(libSources
   ${SOURCE_DIR}/lib/mp4_encryption.cpp
   ${SOURCE_DIR}/lib/mp4_generic.cpp
   ${SOURCE_DIR}/lib/mp4_ms.cpp
+  ${SOURCE_DIR}/lib/mpeg.cpp
   ${SOURCE_DIR}/lib/nal.cpp
   ${SOURCE_DIR}/lib/ogg.cpp
   ${SOURCE_DIR}/lib/procs.cpp

lib/mpeg.cpp

@@ -0,0 +1,63 @@
+#include "mpeg.h"
+
+namespace Mpeg{
+
+  MP2Info parseMP2Header(const std::string &hdr){return parseMP2Header(hdr.c_str());}
+  MP2Info parseMP2Header(const char *hdr){
+    MP2Info res;
+    // mpeg version is on the bits 0x18 of header[1], but only 0x08 is important --> 0 is version 2,
+    // 1 is version 1
+    // leads to 2 - value == version, -1 to get the right index for the array
+    int mpegVersion = 1 - ((hdr[1] >> 3) & 0x01);
+    // samplerate is encoded in bits 0x0C of header[2];
+    res.sampleRate = sampleRates[mpegVersion][((hdr[2] >> 2) & 0x03)] * 1000;
+    res.channels = 2 - (hdr[3] >> 7);
+    return res;
+  }
+
+  void MPEG2Info::clear(){
+    width = 0;
+    height = 0;
+    fps = 0;
+    tempSeq = 0;
+    frameType = 0;
+    isHeader = false;
+  }
+
+  MPEG2Info parseMPEG2Header(const std::string &hdr){return parseMPEG2Header(hdr.data());}
+  MPEG2Info parseMPEG2Header(const char *hdr){
+    MPEG2Info res;
+    parseMPEG2Header(hdr, res);
+    return res;
+  }
+  bool parseMPEG2Header(const char *hdr, MPEG2Info &mpInfo){
+    // Check for start code
+    if (hdr[0] != 0 || hdr[1] != 0 || hdr[2] != 1){return false;}
+    if (hdr[3] == 0xB3){// Sequence header
+      mpInfo.isHeader = true;
+      mpInfo.width = (hdr[4] << 4) | ((hdr[5] >> 4) & 0x0F);
+      mpInfo.height = ((hdr[5] & 0x0F) << 8) | hdr[6];
+      mpInfo.fps = frameRate[hdr[7] & 0x0F];
+      return true;
+    }
+    if (hdr[3] == 0x00){// Picture header
+      mpInfo.tempSeq = (((uint16_t)hdr[4]) << 2) || (hdr[5] >> 6);
+      mpInfo.frameType = (hdr[5] & 0x38) >> 3;
+      return true;
+    }
+    // Not parsed
+    return false;
+  }
+  void parseMPEG2Headers(const char *hdr, uint32_t len, MPEG2Info &mpInfo){
+    mpInfo.clear();
+    for (uint32_t i = 0; i < len-5; ++i){
+      parseMPEG2Header(hdr+i, mpInfo);
+    }
+  }
+  MPEG2Info parseMPEG2Headers(const char *hdr, uint32_t len){
+    MPEG2Info res;
+    parseMPEG2Headers(hdr, len, res);
+    return res;
+  }
+}
+

lib/mpeg.h

@@ -0,0 +1,44 @@
+#include <stdint.h>
+#include <string>
+
+namespace Mpeg{
+  const static double sampleRates[2][3] ={{44.1, 48.0, 32.0},{22.05, 24.0, 16.0}};
+  const static int sampleCounts[2][3] ={{374, 1152, 1152},{384, 1152, 576}};
+  const static int bitRates[2][3][16] ={
+      {{0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, -1},
+       {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, -1},
+       {0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, -1}},
+      {{0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256, -1},
+       {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, -1},
+       {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160, -1}}};
+
+  struct MP2Info{
+    uint64_t sampleRate;
+    uint8_t channels;
+  };
+
+  MP2Info parseMP2Header(const std::string &hdr);
+  MP2Info parseMP2Header(const char *hdr);
+
+  const static double frameRate[16] ={
+      0, 24000.0 / 1001, 24, 25, 30000.0 / 1001, 30, 50, 60000.0 / 1001, 60, 0, 0, 0, 0, 0, 0, 0};
+
+  class MPEG2Info{
+  public:
+    MPEG2Info(){clear();}
+    void clear();
+    uint64_t width;
+    uint64_t height;
+    double fps;
+    uint16_t tempSeq;
+    uint8_t frameType;
+    bool isHeader;
+  };
+
+  MPEG2Info parseMPEG2Header(const std::string &hdr);
+  MPEG2Info parseMPEG2Header(const char *hdr);
+  bool parseMPEG2Header(const char *hdr, MPEG2Info &mpInfo);
+  void parseMPEG2Headers(const char *hdr, uint32_t len, MPEG2Info &mpInfo);
+  MPEG2Info parseMPEG2Headers(const char *hdr, uint32_t len);
+}
+

src/input/input_mp3.cpp

@@ -8,6 +8,7 @@
 #include <mist/stream.h>
 #include <mist/flv_tag.h>
 #include <mist/defines.h>
+#include <mist/mpeg.h>
 
 #include "input_mp3.h"
 
@@ -70,13 +71,9 @@ namespace Mist {
     fread(header, 4, 1, inFile);
     fseek(inFile, filePos, SEEK_SET);
 
-    //mpeg version is on the bits 0x18 of header[1], but only 0x08 is important --> 0 is version 2, 1 is version 1
-    //leads to 2 - value == version, -1 to get the right index for the array
-    int mpegVersion = 1 - ((header[1] >> 3) & 0x01);
-    //samplerate is encoded in bits 0x0C of header[2];
-    myMeta.tracks[1].rate = sampleRates[mpegVersion][((header[2] >> 2) & 0x03)] * 1000;
-    myMeta.tracks[1].channels = 2 - ( header[3] >> 7);
-
+    Mpeg::MP2Info mp2Info = Mpeg::parseMP2Header(header);
+    myMeta.tracks[1].rate = mp2Info.sampleRate;
+    myMeta.tracks[1].channels = mp2Info.channels;
 
     getNext();
     while (thisPacket){