@@ -55,7 +55,7 @@ version <next>:

 - Win64 support for optimized asm functions

 - MJPEG/AVI1 to JPEG/JFIF bitstream filter

 - ASS subtitle encoder and decoder

-- IEC 61937 encapsulation for E-AC3 (for HDMI passthrough)

+- IEC 61937 encapsulation for E-AC3 and TrueHD (for HDMI passthrough)

 - overlay filter added

 - rename aspect filter to setdar, and pixelaspect to setsar

 - IEC 61937 demuxer

@@ -211,6 +211,66 @@ static int spdif_header_aac(AVFormatContext *s, AVPacket *pkt)

     return 0;

 }

+

+/*

+ * It seems Dolby TrueHD frames have to be encapsulated in MAT frames before

+ * they can be encapsulated in IEC 61937.

+ * Here we encapsulate 24 TrueHD frames in a single MAT frame, padding them

+ * to achieve constant rate.

+ * The actual format of a MAT frame is unknown, but the below seems to work.

+ * However, it seems it is not actually necessary for the 24 TrueHD frames to

+ * be in an exact alignment with the MAT frame.

+ */

+#define MAT_FRAME_SIZE          61424

+#define TRUEHD_FRAME_OFFSET     2560

+#define MAT_MIDDLE_CODE_OFFSET  -4

+

+static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)

+{

+    IEC958Context *ctx = s->priv_data;

+    int mat_code_length = 0;

+    const char mat_end_code[16] = { 0xC3, 0xC2, 0xC0, 0xC4, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0x11 };

+

+    if (!ctx->hd_buf_count) {

+        const char mat_start_code[20] = { 0x07, 0x9E, 0x00, 0x03, 0x84, 0x01, 0x01, 0x01, 0x80, 0x00, 0x56, 0xA5, 0x3B, 0xF4, 0x81, 0x83, 0x49, 0x80, 0x77, 0xE0 };

+        mat_code_length = sizeof(mat_start_code) + BURST_HEADER_SIZE;

+        memcpy(ctx->hd_buf, mat_start_code, sizeof(mat_start_code));

+

+    } else if (ctx->hd_buf_count == 12) {

+        const char mat_middle_code[12] = { 0xC3, 0xC1, 0x42, 0x49, 0x3B, 0xFA, 0x82, 0x83, 0x49, 0x80, 0x77, 0xE0 };

+        mat_code_length = sizeof(mat_middle_code) + MAT_MIDDLE_CODE_OFFSET;

+        memcpy(&ctx->hd_buf[12 * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + MAT_MIDDLE_CODE_OFFSET],

+               mat_middle_code, sizeof(mat_middle_code));

+    }

+

+    if (pkt->size > TRUEHD_FRAME_OFFSET - mat_code_length) {

+        /* if such frames exist, we'd need some more complex logic to

+         * distribute the TrueHD frames in the MAT frame */

+        av_log(s, AV_LOG_ERROR, "TrueHD frame too big, %d bytes\n", pkt->size);

+        av_log_ask_for_sample(s, NULL);

+        return -1;

+    }

+

+    memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length],

+           pkt->data, pkt->size);

+    memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size],

+           0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length);

+

+    if (++ctx->hd_buf_count < 24){

+        ctx->pkt_offset = 0;

+        return 0;

+    }

+    memcpy(&ctx->hd_buf[MAT_FRAME_SIZE - sizeof(mat_end_code)], mat_end_code, sizeof(mat_end_code));

+    ctx->hd_buf_count = 0;

+

+    ctx->data_type   = IEC958_TRUEHD;

+    ctx->pkt_offset  = 61440;

+    ctx->out_buf     = ctx->hd_buf;

+    ctx->out_bytes   = MAT_FRAME_SIZE;

+    ctx->length_code = MAT_FRAME_SIZE;

+    return 0;

+}

+

 static int spdif_write_header(AVFormatContext *s)

 {

     IEC958Context *ctx = s->priv_data;

@@ -233,6 +293,12 @@ static int spdif_write_header(AVFormatContext *s)

     case CODEC_ID_AAC:

         ctx->header_info = spdif_header_aac;

         break;

+    case CODEC_ID_TRUEHD:

+        ctx->header_info = spdif_header_truehd;

+        ctx->hd_buf = av_malloc(MAT_FRAME_SIZE);

+        if (!ctx->hd_buf)

+            return AVERROR(ENOMEM);

+        break;

     default:

         av_log(s, AV_LOG_ERROR, "codec not supported\n");

         return -1;