mlpenc: Working MLP/TrueHD encoder

* Multichannel support for TrueHD is experimental

    There should be downmix substreams present for 2+ channel bitstreams,
    but ffmpeg decoder doesn't need it. Will add support for this soon.

* There might be lossless check failures on LFE channels

* 32-bit sample support has been removed for now, will add it later

    While testing, some samples gave lossless check failures when enforcing
    s32. Probably this will also get solved with the LFE issues.
Signed-off-by: Jai Luthra <me@jailuthra.in>

libavcodec/Makefile

@@ -383,6 +383,7 @@ OBJS-$(CONFIG_MJPEG_ENCODER)           += mjpegenc.o mjpegenc_common.o
 OBJS-$(CONFIG_MJPEGB_DECODER)          += mjpegbdec.o
 OBJS-$(CONFIG_MJPEG_VAAPI_ENCODER)     += vaapi_encode_mjpeg.o
 OBJS-$(CONFIG_MLP_DECODER)             += mlpdec.o mlpdsp.o
+OBJS-$(CONFIG_MLP_ENCODER)             += mlpenc.o
 OBJS-$(CONFIG_MMVIDEO_DECODER)         += mmvideo.o
 OBJS-$(CONFIG_MOTIONPIXELS_DECODER)    += motionpixels.o
 OBJS-$(CONFIG_MOVTEXT_DECODER)         += movtextdec.o ass.o
@@ -546,6 +547,7 @@ OBJS-$(CONFIG_TIFF_DECODER)            += tiff.o lzw.o faxcompr.o tiff_data.o ti
 OBJS-$(CONFIG_TIFF_ENCODER)            += tiffenc.o rle.o lzwenc.o tiff_data.o
 OBJS-$(CONFIG_TMV_DECODER)             += tmv.o cga_data.o
 OBJS-$(CONFIG_TRUEHD_DECODER)          += mlpdec.o mlpdsp.o
+OBJS-$(CONFIG_TRUEHD_ENCODER)          += mlpenc.o
 OBJS-$(CONFIG_TRUEMOTION1_DECODER)     += truemotion1.o
 OBJS-$(CONFIG_TRUEMOTION2_DECODER)     += truemotion2.o
 OBJS-$(CONFIG_TRUEMOTION2RT_DECODER)   += truemotion2rt.o

libavcodec/allcodecs.c

@@ -425,7 +425,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER(MACE3,             mace3);
     REGISTER_DECODER(MACE6,             mace6);
     REGISTER_DECODER(METASOUND,         metasound);
-    REGISTER_DECODER(MLP,               mlp);
+    REGISTER_ENCDEC (MLP,               mlp);
     REGISTER_DECODER(MP1,               mp1);
     REGISTER_DECODER(MP1FLOAT,          mp1float);
     REGISTER_ENCDEC (MP2,               mp2);
@@ -454,7 +454,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC (SONIC,             sonic);
     REGISTER_ENCODER(SONIC_LS,          sonic_ls);
     REGISTER_DECODER(TAK,               tak);
-    REGISTER_DECODER(TRUEHD,            truehd);
+    REGISTER_ENCDEC (TRUEHD,            truehd);
     REGISTER_DECODER(TRUESPEECH,        truespeech);
     REGISTER_ENCDEC (TTA,               tta);
     REGISTER_DECODER(TWINVQ,            twinvq);

libavcodec/mlp.c

@@ -41,6 +41,27 @@ const uint8_t ff_mlp_huffman_tables[3][18][2] = {
     }
 };
 
+const ChannelInformation ff_mlp_ch_info[21] = {
+    { 0x01, 0x01, 0x00, 0x1f }, { 0x03, 0x02, 0x00, 0x1b },
+    { 0x07, 0x02, 0x01, 0x1f }, { 0x0F, 0x02, 0x02, 0x19 },
+    { 0x07, 0x02, 0x01, 0x03 }, { 0x0F, 0x02, 0x02, 0x1f },
+    { 0x1F, 0x02, 0x03, 0x01 }, { 0x07, 0x02, 0x01, 0x1a },
+    { 0x0F, 0x02, 0x02, 0x1f }, { 0x1F, 0x02, 0x03, 0x18 },
+    { 0x0F, 0x02, 0x02, 0x02 }, { 0x1F, 0x02, 0x03, 0x1f },
+    { 0x3F, 0x02, 0x04, 0x00 }, { 0x0F, 0x03, 0x01, 0x1f },
+    { 0x1F, 0x03, 0x02, 0x18 }, { 0x0F, 0x03, 0x01, 0x02 },
+    { 0x1F, 0x03, 0x02, 0x1f }, { 0x3F, 0x03, 0x03, 0x00 },
+    { 0x1F, 0x04, 0x01, 0x01 }, { 0x1F, 0x04, 0x01, 0x18 },
+    { 0x3F, 0x04, 0x02, 0x00 },
+};
+
+const uint64_t ff_mlp_channel_layouts[12] = {
+    AV_CH_LAYOUT_MONO, AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_2_1,
+    AV_CH_LAYOUT_QUAD, AV_CH_LAYOUT_2POINT1, AV_CH_LAYOUT_SURROUND,
+    AV_CH_LAYOUT_4POINT0, AV_CH_LAYOUT_5POINT0_BACK, AV_CH_LAYOUT_3POINT1,
+    AV_CH_LAYOUT_4POINT1, AV_CH_LAYOUT_5POINT1_BACK, 0,
+};
+
 static int crc_init = 0;
 #if CONFIG_SMALL
 #define CRC_TABLE_SIZE 257

libavcodec/mlp.h

@@ -76,6 +76,9 @@ typedef struct FilterParams {
     uint8_t     shift; ///< Right shift to apply to output of filter.
 
     int32_t     state[MAX_FIR_ORDER];
+
+    int coeff_bits;
+    int coeff_shift;
 } FilterParams;
 
 /** sample data coding information */
@@ -96,6 +99,43 @@ typedef struct ChannelParams {
  */
 extern const uint8_t ff_mlp_huffman_tables[3][18][2];
 
+typedef struct {
+    uint8_t channel_occupancy;
+    uint8_t group1_channels;
+    uint8_t group2_channels;
+    uint8_t summary_info;
+} ChannelInformation;
+
+/** Tables defining channel information.
+ *
+ *  Possible channel arrangements are:
+ *
+ *  (Group 1)   C
+ *  (Group 1)   L,  R
+ *  (Group 1)   Lf, Rf          /  (Group 2)   S
+ *  (Group 1)   Lf, Rf          /  (Group 2)   Ls, Rs
+ *  (Group 1)   Lf, Rf          /  (Group 2)   LFE
+ *  (Group 1)   Lf, Rf          /  (Group 2)   LFE, S
+ *  (Group 1)   Lf, Rf          /  (Group 2)   LFE, Ls, Rs
+ *  (Group 1)   Lf, Rf          /  (Group 2)   C
+ *  (Group 1)   Lf, Rf          /  (Group 2)   C, S
+ *  (Group 1)   Lf, Rf          /  (Group 2)   C, Ls, Rs
+ *  (Group 1)   Lf, Rf          /  (Group 2)   C, LFE
+ *  (Group 1)   Lf, Rf          /  (Group 2)   C, LFE, S
+ *  (Group 1)   Lf, Rf          /  (Group 2)   C, LFE, Ls,  Rs
+ *  (Group 1)   Lf, Rf  C       /  (Group 2)   S
+ *  (Group 1)   Lf, Rf  C       /  (Group 2)   Ls, Rs
+ *  (Group 1)   Lf, Rf  C       /  (Group 2)   LFE
+ *  (Group 1)   Lf, Rf  C       /  (Group 2)   LFE, S
+ *  (Group 1)   Lf, Rf  C       /  (Group 2)   LFE, Ls, Rs
+ *  (Group 1)   Lf, Rf  Ls  Rs  /  (Group 2)   LFE
+ *  (Group 1)   Lf, Rf  Ls  Rs  /  (Group 2)   C
+ *  (Group 1)   Lf, Rf, Ls, Rs  /  (Group 2)   C, LFE
+ */
+extern const ChannelInformation ff_mlp_ch_info[21];
+
+extern const uint64_t ff_mlp_channel_layouts[12];
+
 /** MLP uses checksums that seem to be based on the standard CRC algorithm, but
  *  are not (in implementation terms, the table lookup and XOR are reversed).
  *  We can implement this behavior using a standard av_crc on all but the