diff --git a/configure b/configure
index 1d87816057..17a7d7945e 100755
--- a/configure
+++ b/configure
@@ -1578,6 +1578,7 @@ CONFIG_EXTRA="
     huffyuvencdsp
     idctdsp
     iirfilter
+    imdct15
     intrax8
     lgplv3
     lpc
@@ -1872,6 +1873,7 @@ nellymoser_encoder_select="audio_frame_queue mdct sinewin"
 nuv_decoder_select="idctdsp lzo"
 on2avc_decoder_select="mdct"
 opus_decoder_deps="avresample"
+opus_decoder_select="imdct15"
 png_decoder_deps="zlib"
 png_encoder_deps="zlib"
 png_encoder_select="huffyuvencdsp"
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index bd38411d77..a38f84042c 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -57,6 +57,7 @@ OBJS-$(CONFIG_HUFFYUVDSP)              += huffyuvdsp.o
 OBJS-$(CONFIG_HUFFYUVENCDSP)           += huffyuvencdsp.o
 OBJS-$(CONFIG_IDCTDSP)                 += idctdsp.o simple_idct.o jrevdct.o
 OBJS-$(CONFIG_IIRFILTER)               += iirfilter.o
+OBJS-$(CONFIG_IMDCT15)                 += imdct15.o
 OBJS-$(CONFIG_INTRAX8)                 += intrax8.o intrax8dsp.o
 OBJS-$(CONFIG_LIBXVID)                 += libxvid_rc.o
 OBJS-$(CONFIG_LPC)                     += lpc.o
@@ -294,8 +295,7 @@ OBJS-$(CONFIG_NELLYMOSER_ENCODER)      += nellymoserenc.o nellymoser.o
 OBJS-$(CONFIG_NUV_DECODER)             += nuv.o rtjpeg.o
 OBJS-$(CONFIG_ON2AVC_DECODER)          += on2avc.o on2avcdata.o
 OBJS-$(CONFIG_OPUS_DECODER)            += opusdec.o opus.o opus_celt.o \
-                                          opus_imdct.o opus_silk.o     \
-                                          vorbis_data.o
+                                          opus_silk.o vorbis_data.o
 OBJS-$(CONFIG_PAF_AUDIO_DECODER)       += pafaudio.o
 OBJS-$(CONFIG_PAF_VIDEO_DECODER)       += pafvideo.o
 OBJS-$(CONFIG_PAM_DECODER)             += pnmdec.o pnm.o
diff --git a/libavcodec/aarch64/Makefile b/libavcodec/aarch64/Makefile
index 964428e35d..2afff297dc 100644
--- a/libavcodec/aarch64/Makefile
+++ b/libavcodec/aarch64/Makefile
@@ -3,11 +3,11 @@ OBJS-$(CONFIG_H264CHROMA)               += aarch64/h264chroma_init_aarch64.o
 OBJS-$(CONFIG_H264DSP)                  += aarch64/h264dsp_init_aarch64.o
 OBJS-$(CONFIG_H264QPEL)                 += aarch64/h264qpel_init_aarch64.o
 OBJS-$(CONFIG_HPELDSP)                  += aarch64/hpeldsp_init_aarch64.o
+OBJS-$(CONFIG_IMDCT15)                  += aarch64/imdct15_init.o
 OBJS-$(CONFIG_MPEGAUDIODSP)             += aarch64/mpegaudiodsp_init.o
 OBJS-$(CONFIG_NEON_CLOBBER_TEST)        += aarch64/neontest.o
 OBJS-$(CONFIG_VIDEODSP)                 += aarch64/videodsp_init.o
 
-OBJS-$(CONFIG_OPUS_DECODER)             += aarch64/opus_imdct_init.o
 OBJS-$(CONFIG_RV40_DECODER)             += aarch64/rv40dsp_init_aarch64.o
 OBJS-$(CONFIG_VC1_DECODER)              += aarch64/vc1dsp_init_aarch64.o
 OBJS-$(CONFIG_VORBIS_DECODER)           += aarch64/vorbisdsp_init.o
@@ -21,8 +21,8 @@ NEON-OBJS-$(CONFIG_H264DSP)             += aarch64/h264dsp_neon.o              \
 NEON-OBJS-$(CONFIG_H264QPEL)            += aarch64/h264qpel_neon.o             \
                                            aarch64/hpeldsp_neon.o
 NEON-OBJS-$(CONFIG_HPELDSP)             += aarch64/hpeldsp_neon.o
+NEON-OBJS-$(CONFIG_IMDCT15)             += aarch64/imdct15_neon.o
 NEON-OBJS-$(CONFIG_MPEGAUDIODSP)        += aarch64/mpegaudiodsp_neon.o
 NEON-OBJS-$(CONFIG_MDCT)                += aarch64/mdct_neon.o
 
-NEON-OBJS-$(CONFIG_OPUS_DECODER)        += aarch64/opus_imdct_neon.o
 NEON-OBJS-$(CONFIG_VORBIS_DECODER)      += aarch64/vorbisdsp_neon.o
diff --git a/libavcodec/aarch64/opus_imdct_init.c b/libavcodec/aarch64/imdct15_init.c
similarity index 66%
rename from libavcodec/aarch64/opus_imdct_init.c
rename to libavcodec/aarch64/imdct15_init.c
index 1a776dca00..38018f2b4a 100644
--- a/libavcodec/aarch64/opus_imdct_init.c
+++ b/libavcodec/aarch64/imdct15_init.c
@@ -21,21 +21,22 @@
 #include "libavutil/cpu.h"
 #include "libavutil/aarch64/cpu.h"
 #include "libavutil/internal.h"
-#include "libavcodec/opus_imdct.h"
+
+#include "libavcodec/imdct15.h"
 
 #include "asm-offsets.h"
 
-AV_CHECK_OFFSET(CeltIMDCTContext, exptab,         CELT_EXPTAB);
-AV_CHECK_OFFSET(CeltIMDCTContext, fft_n,          CELT_FFT_N);
-AV_CHECK_OFFSET(CeltIMDCTContext, len2,           CELT_LEN2);
-AV_CHECK_OFFSET(CeltIMDCTContext, len4,           CELT_LEN4);
-AV_CHECK_OFFSET(CeltIMDCTContext, tmp,            CELT_TMP);
-AV_CHECK_OFFSET(CeltIMDCTContext, twiddle_exptab, CELT_TWIDDLE);
+AV_CHECK_OFFSET(IMDCT15Context, exptab,         CELT_EXPTAB);
+AV_CHECK_OFFSET(IMDCT15Context, fft_n,          CELT_FFT_N);
+AV_CHECK_OFFSET(IMDCT15Context, len2,           CELT_LEN2);
+AV_CHECK_OFFSET(IMDCT15Context, len4,           CELT_LEN4);
+AV_CHECK_OFFSET(IMDCT15Context, tmp,            CELT_TMP);
+AV_CHECK_OFFSET(IMDCT15Context, twiddle_exptab, CELT_TWIDDLE);
 
-void ff_celt_imdct_half_neon(CeltIMDCTContext *s, float *dst, const float *src,
+void ff_celt_imdct_half_neon(IMDCT15Context *s, float *dst, const float *src,
                              ptrdiff_t stride, float scale);
 
-void ff_celt_imdct_init_aarch64(CeltIMDCTContext *s)
+void ff_imdct15_init_aarch64(IMDCT15Context *s)
 {
     int cpu_flags = av_get_cpu_flags();
 
diff --git a/libavcodec/aarch64/opus_imdct_neon.S b/libavcodec/aarch64/imdct15_neon.S
similarity index 100%
rename from libavcodec/aarch64/opus_imdct_neon.S
rename to libavcodec/aarch64/imdct15_neon.S
diff --git a/libavcodec/opus_imdct.c b/libavcodec/imdct15.c
similarity index 91%
rename from libavcodec/opus_imdct.c
rename to libavcodec/imdct15.c
index 38674edd32..e02e9cedf6 100644
--- a/libavcodec/opus_imdct.c
+++ b/libavcodec/imdct15.c
@@ -33,8 +33,8 @@
 #include "libavutil/common.h"
 
 #include "avfft.h"
+#include "imdct15.h"
 #include "opus.h"
-#include "opus_imdct.h"
 
 // minimal iMDCT size to make SIMD opts easier
 #define CELT_MIN_IMDCT_SIZE 120
@@ -66,9 +66,9 @@ do {                                                 \
     (d).im = -ri + ir;                               \
 } while (0)
 
-av_cold void ff_celt_imdct_uninit(CeltIMDCTContext **ps)
+av_cold void ff_imdct15_uninit(IMDCT15Context **ps)
 {
-    CeltIMDCTContext *s = *ps;
+    IMDCT15Context *s = *ps;
     int i;
 
     if (!s)
@@ -84,12 +84,12 @@ av_cold void ff_celt_imdct_uninit(CeltIMDCTContext **ps)
     av_freep(ps);
 }
 
-static void celt_imdct_half(CeltIMDCTContext *s, float *dst, const float *src,
-                            ptrdiff_t stride, float scale);
+static void imdct15_half(IMDCT15Context *s, float *dst, const float *src,
+                         ptrdiff_t stride, float scale);
 
-av_cold int ff_celt_imdct_init(CeltIMDCTContext **ps, int N)
+av_cold int ff_imdct15_init(IMDCT15Context **ps, int N)
 {
-    CeltIMDCTContext *s;
+    IMDCT15Context *s;
     int len2 = 15 * (1 << N);
     int len  = 2 * len2;
     int i, j;
@@ -134,16 +134,17 @@ av_cold int ff_celt_imdct_init(CeltIMDCTContext **ps, int N)
     for (j = 15; j < 19; j++)
         s->exptab[0][j] = s->exptab[0][j - 15];
 
-    s->imdct_half = celt_imdct_half;
+    s->imdct_half = imdct15_half;
 
     if (ARCH_AARCH64)
-        ff_celt_imdct_init_aarch64(s);
+        ff_imdct15_init_aarch64(s);
 
     *ps = s;
 
     return 0;
+
 fail:
-    ff_celt_imdct_uninit(&s);
+    ff_imdct15_uninit(&s);
     return AVERROR(ENOMEM);
 }
 
@@ -180,7 +181,8 @@ static void fft5(FFTComplex *out, const FFTComplex *in, ptrdiff_t stride)
     out[4].im = in[0].im + z[0][3].im + z[1][2].im + z[2][1].im + z[3][0].im;
 }
 
-static void fft15(CeltIMDCTContext *s, FFTComplex *out, const FFTComplex *in, ptrdiff_t stride)
+static void fft15(IMDCT15Context *s, FFTComplex *out, const FFTComplex *in,
+                  ptrdiff_t stride)
 {
     const FFTComplex *exptab = s->exptab[0];
     FFTComplex tmp[5];
@@ -215,7 +217,7 @@ static void fft15(CeltIMDCTContext *s, FFTComplex *out, const FFTComplex *in, pt
 /*
  * FFT of the length 15 * (2^N)
  */
-static void fft_calc(CeltIMDCTContext *s, FFTComplex *out, const FFTComplex *in,
+static void fft_calc(IMDCT15Context *s, FFTComplex *out, const FFTComplex *in,
                      int N, ptrdiff_t stride)
 {
     if (N) {
@@ -241,8 +243,8 @@ static void fft_calc(CeltIMDCTContext *s, FFTComplex *out, const FFTComplex *in,
         fft15(s, out, in, stride);
 }
 
-static void celt_imdct_half(CeltIMDCTContext *s, float *dst, const float *src,
-                            ptrdiff_t stride, float scale)
+static void imdct15_half(IMDCT15Context *s, float *dst, const float *src,
+                         ptrdiff_t stride, float scale)
 {
     FFTComplex *z = (FFTComplex *)dst;
     const int len8 = s->len4 / 2;
diff --git a/libavcodec/opus_imdct.h b/libavcodec/imdct15.h
similarity index 74%
rename from libavcodec/opus_imdct.h
rename to libavcodec/imdct15.h
index d4bff9a152..ed3f0039e8 100644
--- a/libavcodec/opus_imdct.h
+++ b/libavcodec/imdct15.h
@@ -16,14 +16,14 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#ifndef AVCODEC_OPUS_IMDCT_H
-#define AVCODEC_OPUS_IMDCT_H
+#ifndef AVCODEC_IMDCT15_H
+#define AVCODEC_IMDCT15_H
 
 #include <stddef.h>
 
 #include "avfft.h"
 
-typedef struct CeltIMDCTContext {
+typedef struct IMDCT15Context {
     int fft_n;
     int len2;
     int len4;
@@ -37,21 +37,21 @@ typedef struct CeltIMDCTContext {
     /**
      * Calculate the middle half of the iMDCT
      */
-    void (*imdct_half)(struct CeltIMDCTContext *s, float *dst, const float *src,
+    void (*imdct_half)(struct IMDCT15Context *s, float *dst, const float *src,
                        ptrdiff_t src_stride, float scale);
-} CeltIMDCTContext;
+} IMDCT15Context;
 
 /**
  * Init an iMDCT of the length 2 * 15 * (2^N)
  */
-int ff_celt_imdct_init(CeltIMDCTContext **s, int N);
+int ff_imdct15_init(IMDCT15Context **s, int N);
 
 /**
  * Free an iMDCT.
  */
-void ff_celt_imdct_uninit(CeltIMDCTContext **s);
+void ff_imdct15_uninit(IMDCT15Context **s);
 
 
-void ff_celt_imdct_init_aarch64(CeltIMDCTContext *s);
+void ff_imdct15_init_aarch64(IMDCT15Context *s);
 
-#endif /* AVCODEC_OPUS_IMDCT_H */
+#endif /* AVCODEC_IMDCT15_H */
diff --git a/libavcodec/opus_celt.c b/libavcodec/opus_celt.c
index af3e549251..a6220e556c 100644
--- a/libavcodec/opus_celt.c
+++ b/libavcodec/opus_celt.c
@@ -28,8 +28,8 @@
 
 #include "libavutil/float_dsp.h"
 
+#include "imdct15.h"
 #include "opus.h"
-#include "opus_imdct.h"
 
 enum CeltSpread {
     CELT_SPREAD_NONE,
@@ -61,7 +61,7 @@ typedef struct CeltFrame {
 struct CeltContext {
     // constant values that do not change during context lifetime
     AVCodecContext    *avctx;
-    CeltIMDCTContext  *imdct[4];
+    IMDCT15Context    *imdct[4];
     AVFloatDSPContext  dsp;
     int output_channels;
 
@@ -1983,7 +1983,7 @@ int ff_celt_decode_frame(CeltContext *s, OpusRangeCoder *rc,
     int silence = 0;
     int transient = 0;
     int anticollapse = 0;
-    CeltIMDCTContext *imdct;
+    IMDCT15Context *imdct;
     float imdct_scale = 1.0;
 
     if (coded_channels != 1 && coded_channels != 2) {
@@ -2179,7 +2179,7 @@ void ff_celt_free(CeltContext **ps)
         return;
 
     for (i = 0; i < FF_ARRAY_ELEMS(s->imdct); i++)
-        ff_celt_imdct_uninit(&s->imdct[i]);
+        ff_imdct15_uninit(&s->imdct[i]);
 
     av_freep(ps);
 }
@@ -2203,7 +2203,7 @@ int ff_celt_init(AVCodecContext *avctx, CeltContext **ps, int output_channels)
     s->output_channels = output_channels;
 
     for (i = 0; i < FF_ARRAY_ELEMS(s->imdct); i++) {
-        ret = ff_celt_imdct_init(&s->imdct[i], i + 3);
+        ret = ff_imdct15_init(&s->imdct[i], i + 3);
         if (ret < 0)
             goto fail;
     }