path: root/contrib/faac/A01-multichannel-improvements.patch

diff -Naur faac-1.28.old/frontend/main.c faac-1.28.new/frontend/main.c
--- faac-1.28.old/frontend/main.c	2009-01-24 02:10:20.000000000 +0100
+++ faac-1.28.new/frontend/main.c	2012-08-06 21:15:34.000000000 +0200
@@ -858,7 +858,7 @@
       break;
     }
     if (infile->channels >= 6)
-        myFormat->useLfe = 1;
+        myFormat->numLFEChannels = 1;
     myFormat->allowMidside = useMidSide;
     if (bitRate)
         myFormat->bitRate = bitRate / infile->channels;
diff -Naur faac-1.28.old/include/faaccfg.h faac-1.28.new/include/faaccfg.h
--- faac-1.28.old/include/faaccfg.h	2004-07-04 14:12:05.000000000 +0200
+++ faac-1.28.new/include/faaccfg.h	2012-08-06 21:15:34.000000000 +0200
@@ -66,8 +66,14 @@
     /* Allow mid/side coding */
     unsigned int allowMidside;
 
-    /* Use one of the channels as LFE channel */
-    unsigned int useLfe;
+    /* Channel configuration */
+    unsigned int channelConfiguration;
+
+    /* Number of front, side, back & LFE channels */
+    unsigned int numFrontChannels;
+    unsigned int numSideChannels;
+    unsigned int numBackChannels;
+    unsigned int numLFEChannels;
 
     /* Use Temporal Noise Shaping */
     unsigned int useTns;
diff -Naur faac-1.28.old/libfaac/bitstream.c faac-1.28.new/libfaac/bitstream.c
--- faac-1.28.old/libfaac/bitstream.c	2007-06-05 20:59:47.000000000 +0200
+++ faac-1.28.new/libfaac/bitstream.c	2012-08-06 21:15:34.000000000 +0200
@@ -1032,6 +1032,219 @@
     return j;
 }
 
+/* write a program_config_element() */
+int WritePCE(faacEncHandle hEncoder,
+             BitStream *bitStream,
+             int byte_alignment,
+             int instance_tag,
+             int writeFlag)
+{
+    int i;
+    int bits = 0;
+
+    /* we can have up to 29 full-bandwidth channels of each type:
+     * 4 bits -> 0 - 15 elements, 14 CPEs (28 channels) and 1 SCE (1 channel)
+     * we can have up to 3 LFE channels:
+     * 2 bits -> 0 - 3 elements, 3 LFEs (1 channel) */
+    if (hEncoder->config.numFrontChannels > 29) {
+        fprintf(stderr, "WritePCE: too many front channels (%u)\n",
+                hEncoder->config.numFrontChannels);
+        return 0;
+    }
+    if (hEncoder->config.numSideChannels  > 29) {
+        fprintf(stderr, "WritePCE: too many side channels (%u)\n",
+                hEncoder->config.numSideChannels);
+        return 0;
+    }
+    if (hEncoder->config.numBackChannels  > 29) {
+        fprintf(stderr, "WritePCE: too many back channels (%u)\n",
+                hEncoder->config.numBackChannels);
+        return 0;
+    }
+    if (hEncoder->config.numLFEChannels   >  3) {
+        fprintf(stderr, "WritePCE: too many LFE channels (%u)\n",
+                hEncoder->config.numLFEChannels);
+        return 0;
+    }
+    /* program_config_element() shall be used only for the audio object types:
+     * AAC main, AAC SSR, AAC LC and AAC LTP */
+    if (hEncoder->config.aacObjectType > 4) {
+        fprintf(stderr, "WritePCE: unsupported AudioObjectType %u",
+                hEncoder->config.aacObjectType);
+        return 0;
+    }
+
+    /* Determine the channel configuration (see GetChannelInfo) */
+    int sceTag                       = 0;
+    int cpeTag                       = 0;
+    int lfeTag                       = 0;
+    int num_front_channel_elements   = 0;
+    int front_element_is_cpe[15]     = { 0 };
+    int front_element_tag_select[15] = { 0 };
+    int num_side_channel_elements    = 0;
+    int side_element_is_cpe[15]      = { 0 };
+    int side_element_tag_select[15]  = { 0 };
+    int num_back_channel_elements    = 0;
+    int back_element_is_cpe[15]      = { 0 };
+    int back_element_tag_select[15]  = { 0 };
+    int num_lfe_channel_elements     = 0;
+    int lfe_element_tag_select[3]    = { 0 };
+    // Front channels
+    i = hEncoder->config.numFrontChannels;
+    if (i % 2) {
+        front_element_is_cpe[num_front_channel_elements]     = 0;
+        front_element_tag_select[num_front_channel_elements] = sceTag;
+        num_front_channel_elements++;
+        sceTag++;
+        i--;
+    }
+    while (i) {
+        front_element_is_cpe[num_front_channel_elements]     = 1;
+        front_element_tag_select[num_front_channel_elements] = cpeTag;
+        num_front_channel_elements++;
+        cpeTag++;
+        i -= 2;
+    }
+    // Side channels
+    i = hEncoder->config.numSideChannels;
+    while (i > 1) {
+        side_element_is_cpe[num_side_channel_elements]       = 1;
+        side_element_tag_select[num_side_channel_elements]   = cpeTag;
+        num_side_channel_elements++;
+        cpeTag++;
+        i -= 2;
+    }
+    if (i) {
+        side_element_is_cpe[num_side_channel_elements]       = 0;
+        side_element_tag_select[num_side_channel_elements]   = sceTag;
+        num_side_channel_elements++;
+        sceTag++;
+        i--;
+    }
+    // Back channels
+    i = hEncoder->config.numBackChannels;
+    while (i > 1) {
+        back_element_is_cpe[num_back_channel_elements]       = 1;
+        back_element_tag_select[num_back_channel_elements]   = cpeTag;
+        num_back_channel_elements++;
+        cpeTag++;
+        i -= 2;
+    }
+    if (i) {
+        back_element_is_cpe[num_back_channel_elements]       = 0;
+        back_element_tag_select[num_back_channel_elements]   = sceTag;
+        num_back_channel_elements++;
+        sceTag++;
+        i--;
+    }
+    // LFE channels
+    i = hEncoder->config.numLFEChannels;
+    while (i) {
+        lfe_element_tag_select[num_lfe_channel_elements]     = lfeTag;
+        num_lfe_channel_elements++;
+        lfeTag++;
+        i--;
+    }
+
+    /* element_instance_tag */
+    if (writeFlag)
+        PutBit(bitStream, instance_tag, 4);
+    bits =+ 4;
+
+    /* object_type */
+    if (writeFlag)
+        PutBit(bitStream, hEncoder->config.aacObjectType - 1, 2);
+    bits += 2;
+
+    /* sampling_frequency_index */
+    if (writeFlag)
+        PutBit(bitStream, hEncoder->sampleRateIdx, 4);
+    bits += 4;
+
+    /* num_front_channel_elements */
+    if (writeFlag)
+        PutBit(bitStream, num_front_channel_elements, 4);
+    bits += 4;
+
+    /* num_side_channel_elements */
+    if (writeFlag)
+        PutBit(bitStream, num_side_channel_elements, 4);
+    bits += 4;
+
+    /* num_back_channel_elements */
+    if (writeFlag)
+        PutBit(bitStream, num_back_channel_elements, 4);
+    bits += 4;
+
+    /* num_lfe_channel_elements */
+    if (writeFlag)
+        PutBit(bitStream, num_lfe_channel_elements, 2);
+    bits += 2;
+
+    /* num_assoc_data_elements */
+    if (writeFlag)
+        PutBit(bitStream, 0, 3);
+    bits += 3;
+
+    /* num_valid_cc_elements */
+    if (writeFlag)
+        PutBit(bitStream, 0, 4);
+    bits += 4;
+
+    /* mono_mixdown_present */
+    if (writeFlag)
+        PutBit(bitStream, 0, 1);
+    bits++;
+
+    /* stereo_mixdown_present */
+    if (writeFlag)
+        PutBit(bitStream, 0, 1);
+    bits++;
+
+    /* matrix_mixdown_idx_present */
+    if (writeFlag)
+        PutBit(bitStream, 0, 1);
+    bits++;
+
+    /* describe the channel configuration */
+    for (i = 0; i < num_front_channel_elements; i++) {
+        if (writeFlag) {
+            PutBit(bitStream, front_element_is_cpe[i], 1);
+            PutBit(bitStream, front_element_tag_select[i], 4);
+        }
+        bits += 5;
+    }
+    for (i = 0; i < num_side_channel_elements; i++) {
+        if (writeFlag) {
+            PutBit(bitStream, side_element_is_cpe[i], 1);
+            PutBit(bitStream, side_element_tag_select[i], 4);
+        }
+        bits += 5;
+    }
+    for (i = 0; i < num_back_channel_elements; i++) {
+        if (writeFlag) {
+            PutBit(bitStream, back_element_is_cpe[i], 1);
+            PutBit(bitStream, back_element_tag_select[i], 4);
+        }
+        bits += 5;
+    }
+    for (i = 0; i < num_lfe_channel_elements; i++) {
+        if (writeFlag)
+            PutBit(bitStream, lfe_element_tag_select[i], 4);
+        bits += 4;
+    }
+
+    /* byte_alignment() */
+    bits += ByteAlign(bitStream, writeFlag, bits + byte_alignment);
+
+    /* comment_field_bytes */
+    if (writeFlag)
+        PutBit(bitStream, 0, 8);
+    bits += 8;
+
+    return bits;
+}
+
 #ifdef DRM
 /*
     ****************************************************************************
diff -Naur faac-1.28.old/libfaac/bitstream.h faac-1.28.new/libfaac/bitstream.h
--- faac-1.28.old/libfaac/bitstream.h	2004-07-04 14:10:52.000000000 +0200
+++ faac-1.28.new/libfaac/bitstream.h	2012-08-06 21:15:34.000000000 +0200
@@ -164,6 +164,13 @@
            unsigned long data,
            int numBit);
 
+/* write a program_config_element() */
+int WritePCE(faacEncHandle hEncoder,
+             BitStream *bitStream,
+             int byte_alignment,
+             int instance_tag,
+             int writeFlag);
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
diff -Naur faac-1.28.old/libfaac/channels.c faac-1.28.new/libfaac/channels.c
--- faac-1.28.old/libfaac/channels.c	2001-09-04 20:39:35.000000000 +0200
+++ faac-1.28.new/libfaac/channels.c	2012-08-06 21:15:34.000000000 +0200
@@ -28,83 +28,112 @@
 #include "coder.h"
 #include "util.h"
 
-/* If LFE present                                                       */
-/*  Num channels       # of SCE's       # of CPE's       #of LFE's      */
-/*  ============       ==========       ==========       =========      */
-/*      1                  1                0               0           */
-/*      2                  0                1               0           */
-/*      3                  1                1               0           */
-/*      4                  1                1               1           */
-/*      5                  1                2               0           */
-/* For more than 5 channels, use the following elements:                */
-/*      2*N                1                2*(N-1)         1           */
-/*      2*N+1              1                2*N             0           */
-/*                                                                      */
-/* Else:                                                                */
-/*                                                                      */
-/*  Num channels       # of SCE's       # of CPE's       #of LFE's      */
-/*  ============       ==========       ==========       =========      */
-/*      1                  1                0               0           */
-/*      2                  0                1               0           */
-/*      3                  1                1               0           */
-/*      4                  2                1               0           */
-/*      5                  1                2               0           */
-/* For more than 5 channels, use the following elements:                */
-/*      2*N                2                2*(N-1)         0           */
-/*      2*N+1              1                2*N             0           */
-
-void GetChannelInfo(ChannelInfo *channelInfo, int numChannels, int useLfe)
-{
-    int sceTag = 0;
-    int lfeTag = 0;
-    int cpeTag = 0;
-    int numChannelsLeft = numChannels;
+static void addSCE(ChannelInfo *channelInfo, int numChannels, int numChannelsLeft, int tag);
+static void addCPE(ChannelInfo *channelInfo, int numChannels, int numChannelsLeft, int tag);
+static void addLFE(ChannelInfo *channelInfo, int numChannels, int numChannelsLeft, int tag);
 
 
-    /* First element is sce, except for 2 channel case */
-    if (numChannelsLeft != 2) {
-        channelInfo[numChannels-numChannelsLeft].present = 1;
-        channelInfo[numChannels-numChannelsLeft].tag = sceTag++;
-        channelInfo[numChannels-numChannelsLeft].cpe = 0;
-        channelInfo[numChannels-numChannelsLeft].lfe = 0;
+void GetChannelInfo(ChannelInfo *channelInfo, int numFrontChannels, int numSideChannels, int numBackChannels, int numLFEChannels)
+{
+    int i;
+    int sceTag           = 0;
+    int cpeTag           = 0;
+    int lfeTag           = 0;
+    int numChannels      = (numFrontChannels +
+                            numSideChannels  +
+                            numBackChannels  +
+                            numLFEChannels);
+    int numChannelsLeft  = numChannels;
+
+    /* Front channels */
+    i = numFrontChannels;
+    if (i % 2) {
+        // Front Center
+        addSCE(channelInfo, numChannels, numChannelsLeft, sceTag);
         numChannelsLeft--;
+        sceTag++;
+        i--;
+    }
+    while (i) {
+        // Front Left/Right, Front Left/Right of Center, ???
+        addCPE(channelInfo, numChannels, numChannelsLeft, cpeTag);
+        numChannelsLeft -= 2;
+        cpeTag++;
+        i -= 2;
     }
 
-    /* Next elements are cpe's */
-    while (numChannelsLeft > 1) {
-        /* Left channel info */
-        channelInfo[numChannels-numChannelsLeft].present = 1;
-        channelInfo[numChannels-numChannelsLeft].tag = cpeTag++;
-        channelInfo[numChannels-numChannelsLeft].cpe = 1;
-        channelInfo[numChannels-numChannelsLeft].common_window = 0;
-        channelInfo[numChannels-numChannelsLeft].ch_is_left = 1;
-        channelInfo[numChannels-numChannelsLeft].paired_ch = numChannels-numChannelsLeft+1;
-        channelInfo[numChannels-numChannelsLeft].lfe = 0;
+    /* Side channels */
+    i = numSideChannels;
+    while (i > 1) {
+        // Surround Left/Right (if rear surrounds present), ???
+        addCPE(channelInfo, numChannels, numChannelsLeft, cpeTag);
+        numChannelsLeft -= 2;
+        cpeTag++;
+        i -= 2;
+    }
+    if (i) {
+        // ???
+        addSCE(channelInfo, numChannels, numChannelsLeft, sceTag);
         numChannelsLeft--;
+        sceTag++;
+        i--;
+    }
 
-        /* Right channel info */
-        channelInfo[numChannels-numChannelsLeft].present = 1;
-        channelInfo[numChannels-numChannelsLeft].cpe = 1;
-        channelInfo[numChannels-numChannelsLeft].common_window = 0;
-        channelInfo[numChannels-numChannelsLeft].ch_is_left = 0;
-        channelInfo[numChannels-numChannelsLeft].paired_ch = numChannels-numChannelsLeft-1;
-        channelInfo[numChannels-numChannelsLeft].lfe = 0;
+    /* Back channels */
+    i = numBackChannels;
+    while (i > 1) {
+        // Surround Left/Right (if rear surrounds absent), Rear Surround Left/Right, ???
+        addCPE(channelInfo, numChannels, numChannelsLeft, cpeTag);
+        numChannelsLeft -= 2;
+        cpeTag++;
+        i -= 2;
+    }
+    if (i) {
+        // Surround Center
+        addSCE(channelInfo, numChannels, numChannelsLeft, sceTag);
         numChannelsLeft--;
+        sceTag++;
+        i--;
     }
 
-    /* Is there another channel left ? */
-    if (numChannelsLeft) {
-        if (useLfe) {
-            channelInfo[numChannels-numChannelsLeft].present = 1;
-            channelInfo[numChannels-numChannelsLeft].tag = lfeTag++;
-            channelInfo[numChannels-numChannelsLeft].cpe = 0;
-            channelInfo[numChannels-numChannelsLeft].lfe = 1;
-        } else {
-            channelInfo[numChannels-numChannelsLeft].present = 1;
-            channelInfo[numChannels-numChannelsLeft].tag = sceTag++;
-            channelInfo[numChannels-numChannelsLeft].cpe = 0;
-            channelInfo[numChannels-numChannelsLeft].lfe = 0;
-        }
+    /* LFE channel */
+    i = numLFEChannels;
+    while (i) {
+        addLFE(channelInfo, numChannels, numChannelsLeft, lfeTag);
         numChannelsLeft--;
+        lfeTag++;
+        i--;
     }
 }
+
+static void addSCE(ChannelInfo *channelInfo, int numChannels, int numChannelsLeft, int tag) {
+    channelInfo[numChannels-numChannelsLeft].present         = 1;
+    channelInfo[numChannels-numChannelsLeft].cpe             = 0;
+    channelInfo[numChannels-numChannelsLeft].lfe             = 0;
+    channelInfo[numChannels-numChannelsLeft].tag             = tag;
+}
+
+static void addCPE(ChannelInfo *channelInfo, int numChannels, int numChannelsLeft, int tag) {
+    /* Left channel info */
+    channelInfo[numChannels-numChannelsLeft].present         = 1;
+    channelInfo[numChannels-numChannelsLeft].cpe             = 1;
+    channelInfo[numChannels-numChannelsLeft].lfe             = 0;
+    channelInfo[numChannels-numChannelsLeft].tag             = tag;
+    channelInfo[numChannels-numChannelsLeft].ch_is_left      = 1;
+    channelInfo[numChannels-numChannelsLeft].common_window   = 0;
+    channelInfo[numChannels-numChannelsLeft].paired_ch       = numChannels-numChannelsLeft+1;
+    /* Right channel info */
+    channelInfo[numChannels-numChannelsLeft+1].present       = 1;
+    channelInfo[numChannels-numChannelsLeft+1].cpe           = 1;
+    channelInfo[numChannels-numChannelsLeft+1].lfe           = 0;
+    channelInfo[numChannels-numChannelsLeft+1].ch_is_left    = 0;
+    channelInfo[numChannels-numChannelsLeft+1].common_window = 0;
+    channelInfo[numChannels-numChannelsLeft+1].paired_ch     = numChannels-numChannelsLeft;
+}
+
+static void addLFE(ChannelInfo *channelInfo, int numChannels, int numChannelsLeft, int tag) {
+    channelInfo[numChannels-numChannelsLeft].present         = 1;
+    channelInfo[numChannels-numChannelsLeft].cpe             = 0;
+    channelInfo[numChannels-numChannelsLeft].lfe             = 1;
+    channelInfo[numChannels-numChannelsLeft].tag             = tag;
+}
diff -Naur faac-1.28.old/libfaac/channels.h faac-1.28.new/libfaac/channels.h
--- faac-1.28.old/libfaac/channels.h	2003-06-26 21:19:41.000000000 +0200
+++ faac-1.28.new/libfaac/channels.h	2012-08-06 21:15:34.000000000 +0200
@@ -45,7 +45,7 @@
     MSInfo msInfo;
 } ChannelInfo;
 
-void GetChannelInfo(ChannelInfo *channelInfo, int numChannels, int useLfe);
+void GetChannelInfo(ChannelInfo *channelInfo, int numFrontChannels, int numSideChannels, int numBackChannels, int numLFEChannels);
 
 #ifdef __cplusplus
 }
diff -Naur faac-1.28.old/libfaac/frame.c faac-1.28.new/libfaac/frame.c
--- faac-1.28.old/libfaac/frame.c	2004-11-17 15:26:06.000000000 +0100
+++ faac-1.28.new/libfaac/frame.c	2012-08-06 21:15:34.000000000 +0200
@@ -99,21 +99,47 @@
         return -2; /* not supported */
     }
 
-    *pSizeOfDecoderSpecificInfo = 2;
-    *ppBuffer = malloc(2);
+    if (hEncoder->config.channelConfiguration > 7) {
+        fprintf(stderr, "faacEncGetDecoderSpecificInfo: "
+                "invalid channel configuration %u\n",
+                hEncoder->config.channelConfiguration);
+        return -2;
+    } else if (hEncoder->config.channelConfiguration) {
+        // 16 bits
+        *pSizeOfDecoderSpecificInfo = 2;
+    } else {
+        // 16 bits + size of the program_config_element()
+        *pSizeOfDecoderSpecificInfo = 2 + (WritePCE(hEncoder, NULL, 0, 0, 0) / 8);
+    }
 
-    if(*ppBuffer != NULL){
+    *ppBuffer = malloc(*pSizeOfDecoderSpecificInfo);
 
+    if (*ppBuffer != NULL) {
         memset(*ppBuffer,0,*pSizeOfDecoderSpecificInfo);
         pBitStream = OpenBitStream(*pSizeOfDecoderSpecificInfo, *ppBuffer);
         PutBit(pBitStream, hEncoder->config.aacObjectType, 5);
         PutBit(pBitStream, hEncoder->sampleRateIdx, 4);
-        PutBit(pBitStream, hEncoder->numChannels, 4);
+        PutBit(pBitStream, hEncoder->config.channelConfiguration, 4);
+        PutBit(pBitStream, 0, 1); // frameLengthFlag
+        PutBit(pBitStream, 0, 1); // dependsOnCoreCoder
+        PutBit(pBitStream, 0, 1); // extensionFlag
+        if (!hEncoder->config.channelConfiguration) {
+            /* a program_config_element() must be written */
+            if (WritePCE(hEncoder, pBitStream, 0, 0, 1) <= 0) {
+                fprintf(stderr,
+                        "faacEncGetDecoderSpecificInfo: WritePCE() failed!\n");
+                *pSizeOfDecoderSpecificInfo = 0;
+                CloseBitStream(pBitStream);
+                free(*ppBuffer);
+                *ppBuffer = NULL;
+                return -3;
+            }
+        }
         CloseBitStream(pBitStream);
-
         return 0;
     } else {
-        return -3;
+        *pSizeOfDecoderSpecificInfo = 0;
+        return -4;
     }
 }
 
@@ -131,7 +157,6 @@
 	int i;
 
     hEncoder->config.allowMidside = config->allowMidside;
-    hEncoder->config.useLfe = config->useLfe;
     hEncoder->config.useTns = config->useTns;
     hEncoder->config.aacObjectType = config->aacObjectType;
     hEncoder->config.mpegVersion = config->mpegVersion;
@@ -139,6 +164,77 @@
     hEncoder->config.inputFormat = config->inputFormat;
     hEncoder->config.shortctl = config->shortctl;
 
+    if (!config->channelConfiguration) {
+        if (hEncoder->numChannels != (config->numFrontChannels +
+                                      config->numSideChannels +
+                                      config->numBackChannels +
+                                      config->numLFEChannels)) {
+            fprintf(stderr, "faacEncSetConfiguration: "
+                    "numChannels doesn't match the custom channel configuration\n");
+            return 0;
+        }
+        hEncoder->config.numFrontChannels = config->numFrontChannels;
+        hEncoder->config.numSideChannels  = config->numSideChannels;
+        hEncoder->config.numBackChannels  = config->numBackChannels;
+        hEncoder->config.numLFEChannels   = config->numLFEChannels;
+    } else if (config->channelConfiguration > 7) {
+        fprintf(stderr, "faacEncSetConfiguration: "
+                "invalid channel configuration %u\n",
+                config->channelConfiguration);
+        return 0;
+    } else {
+        if ((config->channelConfiguration == 7 && hEncoder->numChannels != 8) ||
+            (config->channelConfiguration != 7 && hEncoder->numChannels != config->channelConfiguration)) {
+            fprintf(stderr, "faacEncSetConfiguration: "
+                    "numChannels doesn't match the channel configuration\n");
+            return 0;
+        }
+        switch (config->channelConfiguration) {
+            case 7:
+                hEncoder->config.numFrontChannels = 5;
+                hEncoder->config.numSideChannels  = 0;
+                hEncoder->config.numBackChannels  = 2;
+                hEncoder->config.numLFEChannels   = 1;
+                break;
+            case 6:
+                hEncoder->config.numFrontChannels = 3;
+                hEncoder->config.numSideChannels  = 0;
+                hEncoder->config.numBackChannels  = 2;
+                hEncoder->config.numLFEChannels   = 1;
+                break;
+            case 5:
+                hEncoder->config.numFrontChannels = 3;
+                hEncoder->config.numSideChannels  = 0;
+                hEncoder->config.numBackChannels  = 2;
+                hEncoder->config.numLFEChannels   = 0;
+                break;
+            case 4:
+                hEncoder->config.numFrontChannels = 3;
+                hEncoder->config.numSideChannels  = 0;
+                hEncoder->config.numBackChannels  = 1;
+                hEncoder->config.numLFEChannels   = 0;
+                break;
+            case 3:
+                hEncoder->config.numFrontChannels = 3;
+                hEncoder->config.numSideChannels  = 0;
+                hEncoder->config.numBackChannels  = 0;
+                hEncoder->config.numLFEChannels   = 0;
+                break;
+            case 2:
+                hEncoder->config.numFrontChannels = 2;
+                hEncoder->config.numSideChannels  = 0;
+                hEncoder->config.numBackChannels  = 0;
+                hEncoder->config.numLFEChannels   = 0;
+                break;
+            case 1:
+                hEncoder->config.numFrontChannels = 1;
+                hEncoder->config.numSideChannels  = 0;
+                hEncoder->config.numBackChannels  = 0;
+                hEncoder->config.numLFEChannels   = 0;
+                break;
+        }
+    }
+
     assert((hEncoder->config.outputFormat == 0) || (hEncoder->config.outputFormat == 1));
 
     switch( hEncoder->config.inputFormat )
@@ -306,6 +402,12 @@
     *maxOutputBytes += 1; /* for CRC */
 #endif
 
+    if (!numChannels || numChannels > 64) {
+        fprintf(stderr, "faacEncOpen: invalid number of channels %u\n",
+                numChannels);
+        return NULL;
+    }
+
     hEncoder = (faacEncStruct*)AllocMemory(sizeof(faacEncStruct));
     SetMemory(hEncoder, 0, sizeof(faacEncStruct));
 
@@ -324,7 +426,6 @@
     hEncoder->config.mpegVersion = MPEG4;
     hEncoder->config.aacObjectType = LTP;
     hEncoder->config.allowMidside = 1;
-    hEncoder->config.useLfe = 1;
     hEncoder->config.useTns = 0;
     hEncoder->config.bitRate = 0; /* default bitrate / channel */
     hEncoder->config.bandWidth = bwfac * hEncoder->sampleRate;
@@ -340,6 +441,91 @@
 	/* default channel map is straight-through */
 	for( channel = 0; channel < 64; channel++ )
 		hEncoder->config.channel_map[channel] = channel;
+
+    /* Define a sensible default channel configuration */
+    if (numChannels <= 6 || numChannels == 8) {
+        switch (numChannels) {
+            case 8:
+                hEncoder->config.channelConfiguration = 7;
+                hEncoder->config.numFrontChannels     = 5;
+                hEncoder->config.numSideChannels      = 0;
+                hEncoder->config.numBackChannels      = 2;
+                hEncoder->config.numLFEChannels       = 1;
+                break;
+            case 6:
+                hEncoder->config.channelConfiguration = 6;
+                hEncoder->config.numFrontChannels     = 3;
+                hEncoder->config.numSideChannels      = 0;
+                hEncoder->config.numBackChannels      = 2;
+                hEncoder->config.numLFEChannels       = 1;
+                break;
+            case 5:
+                hEncoder->config.channelConfiguration = 5;
+                hEncoder->config.numFrontChannels     = 3;
+                hEncoder->config.numSideChannels      = 0;
+                hEncoder->config.numBackChannels      = 2;
+                hEncoder->config.numLFEChannels       = 0;
+                break;
+            case 4:
+                hEncoder->config.channelConfiguration = 4;
+                hEncoder->config.numFrontChannels     = 3;
+                hEncoder->config.numSideChannels      = 0;
+                hEncoder->config.numBackChannels      = 1;
+                hEncoder->config.numLFEChannels       = 0;
+                break;
+            case 3:
+                hEncoder->config.channelConfiguration = 3;
+                hEncoder->config.numFrontChannels     = 3;
+                hEncoder->config.numSideChannels      = 0;
+                hEncoder->config.numBackChannels      = 0;
+                hEncoder->config.numLFEChannels       = 0;
+                break;
+            case 2:
+                hEncoder->config.channelConfiguration = 2;
+                hEncoder->config.numFrontChannels     = 2;
+                hEncoder->config.numSideChannels      = 0;
+                hEncoder->config.numBackChannels      = 0;
+                hEncoder->config.numLFEChannels       = 0;
+                break;
+            case 1:
+                hEncoder->config.channelConfiguration = 1;
+                hEncoder->config.numFrontChannels     = 1;
+                hEncoder->config.numSideChannels      = 0;
+                hEncoder->config.numBackChannels      = 0;
+                hEncoder->config.numLFEChannels       = 0;
+                break;
+        }
+    } else {
+        hEncoder->config.channelConfiguration = 0;
+        hEncoder->config.numFrontChannels     = 0;
+        hEncoder->config.numSideChannels      = 0;
+        hEncoder->config.numBackChannels      = 0;
+        hEncoder->config.numLFEChannels       = 0;
+        for (channel = numChannels; channel > 0; channel--) {
+            // 7 channels:   7.0 (C   L   R   Ls  Rs  Rls Rrs)
+            // 9 channels:   9.0 (Lc  Rc  L   R   Ls  Rs  Rls Rrs Cs)
+            // 10 channels: 10.0 (C   Lc  Rc  L   R   Ls  Rs  Rls Rrs Cs)
+            // for more than 10 channels, use faacEncSetConfiguration()
+            if (hEncoder->config.numFrontChannels        < 3) {
+                // C, L, R
+                hEncoder->config.numFrontChannels++;
+            } else if (hEncoder->config.numBackChannels  < 2) {
+                // Ls or Rls, Rs or Rrs
+                hEncoder->config.numBackChannels++;
+            } else if (hEncoder->config.numSideChannels  < 2) {
+                // Ls, Rs
+                hEncoder->config.numSideChannels++;
+            } else if (hEncoder->config.numBackChannels  < 3) {
+                // Cs
+                hEncoder->config.numBackChannels++;
+            } else if (hEncoder->config.numFrontChannels < 5) {
+                // Lc, Rc
+                hEncoder->config.numFrontChannels++;
+            } else {
+                break;
+            }
+        }
+    }
 	
     /*
         by default we have to be compatible with all previous software
@@ -459,14 +645,13 @@
     double fix;
 #endif
 
-    /* local copy's of parameters */
+    /* local copies of parameters */
     ChannelInfo *channelInfo = hEncoder->channelInfo;
     CoderInfo *coderInfo = hEncoder->coderInfo;
     unsigned int numChannels = hEncoder->numChannels;
     unsigned int sampleRate = hEncoder->sampleRate;
     unsigned int aacObjectType = hEncoder->config.aacObjectType;
     unsigned int mpegVersion = hEncoder->config.mpegVersion;
-    unsigned int useLfe = hEncoder->config.useLfe;
     unsigned int useTns = hEncoder->config.useTns;
     unsigned int allowMidside = hEncoder->config.allowMidside;
     unsigned int bandWidth = hEncoder->config.bandWidth;
@@ -484,7 +669,11 @@
         return 0;
 
     /* Determine the channel configuration */
-    GetChannelInfo(channelInfo, numChannels, useLfe);
+    GetChannelInfo(channelInfo,
+                   hEncoder->config.numFrontChannels,
+                   hEncoder->config.numSideChannels,
+                   hEncoder->config.numBackChannels,
+                   hEncoder->config.numLFEChannels);
 
     /* Update current sample buffers */
     for (channel = 0; channel < numChannels; channel++)