lavr: temporarily store custom matrix in AVAudioResampleContext

This allows AudioMix to be treated the same way as other conversion contexts
and removes the requirement to allocate it at the same time as the
AVAudioResampleContext.

The current matrix get/set functions are split between the public interface
and AudioMix private functions.

1 files changed, 128 insertions, 26 deletions

diff --git a/libavresample/audio_mix.c b/libavresample/audio_mix.c
index dd2f33d27f..3b39ceeca5 100644
--- a/libavresample/audio_mix.c
+++ b/libavresample/audio_mix.c
@@ -302,27 +302,37 @@ static int mix_function_init(AudioMix *am)
     return 0;
 }
 
-int ff_audio_mix_init(AVAudioResampleContext *avr)
+AudioMix *ff_audio_mix_alloc(AVAudioResampleContext *avr)
 {
+    AudioMix *am;
     int ret;
 
+    am = av_mallocz(sizeof(*am));
+    if (!am)
+        return NULL;
+    am->avr = avr;
+
     if (avr->internal_sample_fmt != AV_SAMPLE_FMT_S16P &&
         avr->internal_sample_fmt != AV_SAMPLE_FMT_FLTP) {
         av_log(avr, AV_LOG_ERROR, "Unsupported internal format for "
                "mixing: %s\n",
                av_get_sample_fmt_name(avr->internal_sample_fmt));
-        return AVERROR(EINVAL);
+        goto error;
     }
 
+    am->fmt          = avr->internal_sample_fmt;
+    am->coeff_type   = avr->mix_coeff_type;
+    am->in_layout    = avr->in_channel_layout;
+    am->out_layout   = avr->out_channel_layout;
+    am->in_channels  = avr->in_channels;
+    am->out_channels = avr->out_channels;
+
     /* build matrix if the user did not already set one */
-    if (avr->am->matrix) {
-        if (avr->am->coeff_type != avr->mix_coeff_type      ||
-            avr->am->in_layout  != avr->in_channel_layout   ||
-            avr->am->out_layout != avr->out_channel_layout) {
-            av_log(avr, AV_LOG_ERROR,
-                   "Custom matrix does not match current parameters\n");
-            return AVERROR(EINVAL);
-        }
+    if (avr->mix_matrix) {
+        ret = ff_audio_mix_set_matrix(am, avr->mix_matrix, avr->in_channels);
+        if (ret < 0)
+            goto error;
+        av_freep(&avr->mix_matrix);
     } else {
         int i, j;
         char in_layout_name[128];
@@ -330,7 +340,7 @@ int ff_audio_mix_init(AVAudioResampleContext *avr)
         double *matrix_dbl = av_mallocz(avr->out_channels * avr->in_channels *
                                         sizeof(*matrix_dbl));
         if (!matrix_dbl)
-            return AVERROR(ENOMEM);
+            goto error;
 
         ret = avresample_build_matrix(avr->in_channel_layout,
                                       avr->out_channel_layout,
@@ -343,7 +353,7 @@ int ff_audio_mix_init(AVAudioResampleContext *avr)
                                       avr->matrix_encoding);
         if (ret < 0) {
             av_free(matrix_dbl);
-            return ret;
+            goto error;
         }
 
         av_get_channel_layout_string(in_layout_name, sizeof(in_layout_name),
@@ -360,32 +370,33 @@ int ff_audio_mix_init(AVAudioResampleContext *avr)
             av_log(avr, AV_LOG_DEBUG, "\n");
         }
 
-        ret = avresample_set_matrix(avr, matrix_dbl, avr->in_channels);
+        ret = ff_audio_mix_set_matrix(am, matrix_dbl, avr->in_channels);
         if (ret < 0) {
             av_free(matrix_dbl);
-            return ret;
+            goto error;
         }
         av_free(matrix_dbl);
     }
 
-    avr->am->fmt          = avr->internal_sample_fmt;
-    avr->am->coeff_type   = avr->mix_coeff_type;
-    avr->am->in_layout    = avr->in_channel_layout;
-    avr->am->out_layout   = avr->out_channel_layout;
-    avr->am->in_channels  = avr->in_channels;
-    avr->am->out_channels = avr->out_channels;
-
-    ret = mix_function_init(avr->am);
+    ret = mix_function_init(am);
     if (ret < 0)
-        return ret;
+        goto error;
 
-    return 0;
+    return am;
+
+error:
+    av_free(am);
+    return NULL;
 }
 
-void ff_audio_mix_close(AudioMix *am)
+void ff_audio_mix_free(AudioMix **am_p)
 {
-    if (!am)
+    AudioMix *am;
+
+    if (!*am_p)
         return;
+    am = *am_p;
+
     if (am->matrix) {
         av_free(am->matrix[0]);
         am->matrix = NULL;
@@ -393,6 +404,8 @@ void ff_audio_mix_close(AudioMix *am)
     memset(am->matrix_q8,  0, sizeof(am->matrix_q8 ));
     memset(am->matrix_q15, 0, sizeof(am->matrix_q15));
     memset(am->matrix_flt, 0, sizeof(am->matrix_flt));
+
+    av_freep(am_p);
 }
 
 int ff_audio_mix(AudioMix *am, AudioData *src)
@@ -424,3 +437,92 @@ int ff_audio_mix(AudioMix *am, AudioData *src)
 
     return 0;
 }
+
+int ff_audio_mix_get_matrix(AudioMix *am, double *matrix, int stride)
+{
+    int i, o;
+
+    if ( am->in_channels <= 0 ||  am->in_channels > AVRESAMPLE_MAX_CHANNELS ||
+        am->out_channels <= 0 || am->out_channels > AVRESAMPLE_MAX_CHANNELS) {
+        av_log(am, AV_LOG_ERROR, "Invalid channel counts\n");
+        return AVERROR(EINVAL);
+    }
+
+#define GET_MATRIX_CONVERT(suffix, scale)                                   \
+    if (!am->matrix_ ## suffix[0]) {                                        \
+        av_log(am, AV_LOG_ERROR, "matrix is not set\n");                    \
+        return AVERROR(EINVAL);                                             \
+    }                                                                       \
+    for (o = 0; o < am->out_channels; o++)                                  \
+        for (i = 0; i < am->in_channels; i++)                               \
+            matrix[o * stride + i] = am->matrix_ ## suffix[o][i] * (scale);
+
+    switch (am->coeff_type) {
+    case AV_MIX_COEFF_TYPE_Q8:
+        GET_MATRIX_CONVERT(q8, 1.0 / 256.0);
+        break;
+    case AV_MIX_COEFF_TYPE_Q15:
+        GET_MATRIX_CONVERT(q15, 1.0 / 32768.0);
+        break;
+    case AV_MIX_COEFF_TYPE_FLT:
+        GET_MATRIX_CONVERT(flt, 1.0);
+        break;
+    default:
+        av_log(am, AV_LOG_ERROR, "Invalid mix coeff type\n");
+        return AVERROR(EINVAL);
+    }
+
+    return 0;
+}
+
+int ff_audio_mix_set_matrix(AudioMix *am, const double *matrix, int stride)
+{
+    int i, o;
+
+    if ( am->in_channels <= 0 ||  am->in_channels > AVRESAMPLE_MAX_CHANNELS ||
+        am->out_channels <= 0 || am->out_channels > AVRESAMPLE_MAX_CHANNELS) {
+        av_log(am, AV_LOG_ERROR, "Invalid channel counts\n");
+        return AVERROR(EINVAL);
+    }
+
+    if (am->matrix) {
+        av_free(am->matrix[0]);
+        am->matrix = NULL;
+    }
+
+#define CONVERT_MATRIX(type, expr)                                          \
+    am->matrix_## type[0] = av_mallocz(am->out_channels * am->in_channels * \
+                                       sizeof(*am->matrix_## type[0]));     \
+    if (!am->matrix_## type[0])                                             \
+        return AVERROR(ENOMEM);                                             \
+    for (o = 0; o < am->out_channels; o++) {                                \
+        if (o > 0)                                                          \
+            am->matrix_## type[o] = am->matrix_## type[o - 1] +             \
+                                    am->in_channels;                        \
+        for (i = 0; i < am->in_channels; i++) {                             \
+            double v = matrix[o * stride + i];                              \
+            am->matrix_## type[o][i] = expr;                                \
+        }                                                                   \
+    }                                                                       \
+    am->matrix = (void **)am->matrix_## type;
+
+    switch (am->coeff_type) {
+    case AV_MIX_COEFF_TYPE_Q8:
+        CONVERT_MATRIX(q8, av_clip_int16(lrint(256.0 * v)))
+        break;
+    case AV_MIX_COEFF_TYPE_Q15:
+        CONVERT_MATRIX(q15, av_clipl_int32(llrint(32768.0 * v)))
+        break;
+    case AV_MIX_COEFF_TYPE_FLT:
+        CONVERT_MATRIX(flt, v)
+        break;
+    default:
+        av_log(am, AV_LOG_ERROR, "Invalid mix coeff type\n");
+        return AVERROR(EINVAL);
+    }
+
+    /* TODO: detect situations where we can just swap around pointers
+             instead of doing matrix multiplications with 0.0 and 1.0 */
+
+    return 0;
+}