@@ -384,9 +384,6 @@ The channel remapping will be effective if, and only if:

 @itemize

 @item gain coefficients are zeroes or ones,

 @item only one input per channel output,

-@item the number of output channels is supported by libswresample (16 at the

-      moment)

-@c if SWR_CH_MAX changes, fix the line above.

 @end itemize

 If all these conditions are satisfied, the filter will notify the user ("Pure

@@ -234,18 +234,29 @@ static int config_props(AVFilterLink *link)

             }

         }

     }

-    // gains are pure, init the channel mapping

-    if (pan->pure_gains) {

+        /* TODO reindent */

         // sanity check; can't be done in query_formats since the inlink

         // channel layout is unknown at that time

-        if (pan->nb_input_channels > SWR_CH_MAX) {

+        if (pan->nb_input_channels > SWR_CH_MAX ||

+            pan->nb_output_channels > SWR_CH_MAX) {

             av_log(ctx, AV_LOG_ERROR,

                    "libswresample support a maximum of %d channels. "

                    "Feel free to ask for a higher limit.\n", SWR_CH_MAX);

             return AVERROR_PATCHWELCOME;

         }

+        // init libswresample context

+        pan->swr = swr_alloc_set_opts(pan->swr,

+                                      pan->out_channel_layout, link->format, link->sample_rate,

+                                      link->channel_layout,    link->format, link->sample_rate,

+                                      0, ctx);

+        if (!pan->swr)

+            return AVERROR(ENOMEM);

+

+    // gains are pure, init the channel mapping

+    if (pan->pure_gains) {

+

         // get channel map from the pure gains

         for (i = 0; i < pan->nb_output_channels; i++) {

             int ch_id = -1;

@@ -258,19 +269,9 @@ static int config_props(AVFilterLink *link)

             pan->channel_map[i] = ch_id;

         }

-        // init libswresample context

-        pan->swr = swr_alloc_set_opts(pan->swr,

-                                      pan->out_channel_layout, link->format, link->sample_rate,

-                                      link->channel_layout,    link->format, link->sample_rate,

-                                      0, ctx);

-        if (!pan->swr)

-            return AVERROR(ENOMEM);

         av_opt_set_int(pan->swr, "icl", pan->out_channel_layout, 0);

         av_opt_set_int(pan->swr, "uch", pan->nb_output_channels, 0);

         swr_set_channel_mapping(pan->swr, pan->channel_map);

-        r = swr_init(pan->swr);

-        if (r < 0)

-            return r;

     } else {

         // renormalize

         for (i = 0; i < pan->nb_output_channels; i++) {

@@ -289,7 +290,16 @@ static int config_props(AVFilterLink *link)

             for (j = 0; j < pan->nb_input_channels; j++)

                 pan->gain.d[i][j] /= t;

         }

+        av_opt_set_int(pan->swr, "icl", link->channel_layout, 0);

+        av_opt_set_int(pan->swr, "ocl", pan->out_channel_layout, 0);

+        swr_set_matrix(pan->swr, pan->gain.d[0],

+                       pan->gain.d[1] - pan->gain.d[0]);

     }

+

+    r = swr_init(pan->swr);

+    if (r < 0)

+        return r;

+

     // summary

     for (i = 0; i < pan->nb_output_channels; i++) {

         cur = buf;

@@ -331,30 +341,6 @@ static void filter_samples_channel_mapping(PanContext *pan,

     swr_convert(pan->swr, outsamples->data, n, (void *)insamples->data, n);

 }

-static void filter_samples_panning(PanContext *pan,

-                                   AVFilterBufferRef *outsamples,

-                                   AVFilterBufferRef *insamples,

-                                   int n)

-{

-    int i, o;

-

-    /* input */

-    const int16_t *in     = (int16_t *)insamples->data[0];

-    const int16_t *in_end = in + n * pan->nb_input_channels;

-

-    /* output */

-    int16_t *out = (int16_t *)outsamples->data[0];

-

-    for (; in < in_end; in += pan->nb_input_channels) {

-        for (o = 0; o < pan->nb_output_channels; o++) {

-            int v = 0;

-            for (i = 0; i < pan->nb_input_channels; i++)

-                v += pan->gain.i[o][i] * in[i];

-            *(out++) = v >> 8;

-        }

-    }

-}

-

 static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)

 {

     int n = insamples->audio->nb_samples;

@@ -379,21 +365,12 @@ static int query_formats(AVFilterContext *ctx)

     AVFilterLink *outlink = ctx->outputs[0];

     AVFilterFormats *formats;

-    if (pan->nb_output_channels <= SWR_CH_MAX)

+        /* TODO reindent */

         pan->pure_gains = are_gains_pure(pan);

-    if (pan->pure_gains) {

         /* libswr supports any sample and packing formats */

         avfilter_set_common_sample_formats(ctx, avfilter_make_all_formats(AVMEDIA_TYPE_AUDIO));

         avfilter_set_common_packing_formats(ctx, avfilter_make_all_packing_formats());

         pan->filter_samples = filter_samples_channel_mapping;

-    } else {

-        const enum AVSampleFormat sample_fmts[] = {AV_SAMPLE_FMT_S16, -1};

-        const int                packing_fmts[] = {AVFILTER_PACKED,   -1};

-

-        avfilter_set_common_sample_formats (ctx, avfilter_make_format_list(sample_fmts));

-        avfilter_set_common_packing_formats(ctx, avfilter_make_format_list(packing_fmts));

-        pan->filter_samples = filter_samples_panning;

-    }

     // inlink supports any channel layout

     formats = avfilter_make_all_channel_layouts();