ac3dec: export center & suroundmix levels

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/ac3dec.c

@@ -1382,6 +1382,10 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
         avctx->channels = s->out_channels;
         avctx->channel_layout = s->channel_layout;
 
+        s->loro_center_mix_level   = gain_levels[  center_levels[s->  center_mix_level]];
+        s->loro_surround_mix_level = gain_levels[surround_levels[s->surround_mix_level]];
+        s->ltrt_center_mix_level   = LEVEL_MINUS_3DB;
+        s->ltrt_surround_mix_level = LEVEL_MINUS_3DB;
         /* set downmixing coefficients if needed */
         if(s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
                 s->fbw_channels == s->out_channels)) {
@@ -1443,6 +1447,13 @@ static av_cold int ac3_decode_end(AVCodecContext *avctx)
 #define PAR (AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM)
 static const AVOption options[] = {
     { "drc_scale", "percentage of dynamic range compression to apply", OFFSET(drc_scale), FF_OPT_TYPE_FLOAT, {1.0}, 0.0, 1.0, PAR },
+
+{"dmix_mode", "Preferred Stereo Downmix Mode", OFFSET(preferred_stereo_downmix), FF_OPT_TYPE_INT, {.dbl = -1 }, -1, 2, 0, "dmix_mode"},
+{"ltrt_cmixlev",   "Lt/Rt Center Mix Level",   OFFSET(ltrt_center_mix_level),    FF_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
+{"ltrt_surmixlev", "Lt/Rt Surround Mix Level", OFFSET(ltrt_surround_mix_level),  FF_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
+{"loro_cmixlev",   "Lo/Ro Center Mix Level",   OFFSET(loro_center_mix_level),    FF_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
+{"loro_surmixlev", "Lo/Ro Surround Mix Level", OFFSET(loro_surround_mix_level),  FF_OPT_TYPE_FLOAT, {.dbl = -1.0 }, -1.0, 2.0, 0},
+
     { NULL},
 };
 

libavcodec/ac3dec.h

@@ -88,6 +88,12 @@ typedef struct {
     int eac3;                               ///< indicates if current frame is E-AC-3
 ///@}
 
+    int preferred_stereo_downmix;
+    float ltrt_center_mix_level;
+    float ltrt_surround_mix_level;
+    float loro_center_mix_level;
+    float loro_surround_mix_level;
+
 ///@name Frame syntax parameters
     int snr_offset_strategy;                ///< SNR offset strategy                    (snroffststr)
     int block_switch_syntax;                ///< block switch syntax enabled            (blkswe)