lavfi: support unknown channel layouts.

libavfilter/audio.c

@@ -44,7 +44,7 @@ AVFilterBufferRef *ff_default_get_audio_buffer(AVFilterLink *link, int perms,
     AVFilterBufferRef *samplesref = NULL;
     uint8_t **data;
     int planar      = av_sample_fmt_is_planar(link->format);
-    int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout);
+    int nb_channels = link->channels;
     int planes      = planar ? nb_channels : 1;
     int linesize;
     int full_perms = AV_PERM_READ | AV_PERM_WRITE | AV_PERM_PRESERVE |

libavfilter/avcodec.c

@@ -96,9 +96,6 @@ AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_frame(const AVFrame *frame
     int channels = av_frame_get_channels(frame);
     int64_t layout = av_frame_get_channel_layout(frame);
 
-    if(av_frame_get_channels(frame) > 8) // libavfilter does not suport more than 8 channels FIXME, remove once libavfilter is fixed
-        return NULL;
-
     if (layout && av_get_channel_layout_nb_channels(layout) != av_frame_get_channels(frame)) {
         av_log(0, AV_LOG_ERROR, "Layout indicates a different number of channels than actually present\n");
         return NULL;

libavfilter/avfiltergraph.c

@@ -185,9 +185,24 @@ AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
     return NULL;
 }
 
+static void sanitize_channel_layouts(void *log, AVFilterChannelLayouts *l)
+{
+    if (!l)
+        return;
+    if (l->nb_channel_layouts) {
+        if (l->all_layouts || l->all_counts)
+            av_log(log, AV_LOG_WARNING, "All layouts set on non-empty list\n");
+        l->all_layouts = l->all_counts = 0;
+    } else {
+        if (l->all_counts && !l->all_layouts)
+            av_log(log, AV_LOG_WARNING, "All counts without all layouts\n");
+        l->all_layouts = 1;
+    }
+}
+
 static int filter_query_formats(AVFilterContext *ctx)
 {
-    int ret;
+    int ret, i;
     AVFilterFormats *formats;
     AVFilterChannelLayouts *chlayouts;
     AVFilterFormats *samplerates;
@@ -201,6 +216,11 @@ static int filter_query_formats(AVFilterContext *ctx)
         return ret;
     }
 
+    for (i = 0; i < ctx->nb_inputs; i++)
+        sanitize_channel_layouts(ctx, ctx->inputs[i]->out_channel_layouts);
+    for (i = 0; i < ctx->nb_outputs; i++)
+        sanitize_channel_layouts(ctx, ctx->outputs[i]->in_channel_layouts);
+
     formats = ff_all_formats(type);
     if (!formats)
         return AVERROR(ENOMEM);
@@ -470,7 +490,7 @@ static int pick_format(AVFilterLink *link, AVFilterLink *ref)
         link->in_samplerates->format_count = 1;
         link->sample_rate = link->in_samplerates->formats[0];
 
-        if (!link->in_channel_layouts->nb_channel_layouts) {
+        if (link->in_channel_layouts->all_layouts) {
             av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout for"
                    "the link between filters %s and %s.\n", link->src->name,
                    link->dst->name);
@@ -478,6 +498,9 @@ static int pick_format(AVFilterLink *link, AVFilterLink *ref)
         }
         link->in_channel_layouts->nb_channel_layouts = 1;
         link->channel_layout = link->in_channel_layouts->channel_layouts[0];
+        if ((link->channels = FF_LAYOUT2COUNT(link->channel_layout)))
+            link->channel_layout = 0;
+        else
             link->channels = av_get_channel_layout_nb_channels(link->channel_layout);
     }
 
@@ -534,8 +557,42 @@ static int reduce_formats_on_filter(AVFilterContext *filter)
                    format_count, ff_add_format);
     REDUCE_FORMATS(int,      AVFilterFormats,        samplerates,     formats,
                    format_count, ff_add_format);
-    REDUCE_FORMATS(uint64_t, AVFilterChannelLayouts, channel_layouts,
-                   channel_layouts, nb_channel_layouts, ff_add_channel_layout);
+
+    /* reduce channel layouts */
+    for (i = 0; i < filter->nb_inputs; i++) {
+        AVFilterLink *inlink = filter->inputs[i];
+        uint64_t fmt;
+
+        if (!inlink->out_channel_layouts ||
+            inlink->out_channel_layouts->nb_channel_layouts != 1)
+            continue;
+        fmt = inlink->out_channel_layouts->channel_layouts[0];
+
+        for (j = 0; j < filter->nb_outputs; j++) {
+            AVFilterLink *outlink = filter->outputs[j];
+            AVFilterChannelLayouts *fmts;
+
+            fmts = outlink->in_channel_layouts;
+            if (inlink->type != outlink->type || fmts->nb_channel_layouts == 1)
+                continue;
+
+            if (fmts->all_layouts) {
+                /* Turn the infinite list into a singleton */
+                fmts->all_layouts = fmts->all_counts  = 0;
+                ff_add_channel_layout(&outlink->in_channel_layouts, fmt);
+                break;
+            }
+
+            for (k = 0; k < outlink->in_channel_layouts->nb_channel_layouts; k++) {
+                if (fmts->channel_layouts[k] == fmt) {
+                    fmts->channel_layouts[0]  = fmt;
+                    fmts->nb_channel_layouts = 1;
+                    ret = 1;
+                    break;
+                }
+            }
+        }
+    }
 
     return ret;
 }
@@ -663,7 +720,23 @@ static void swap_channel_layouts_on_filter(AVFilterContext *filter)
             int out_channels      = av_get_channel_layout_nb_channels(out_chlayout);
             int count_diff        = out_channels - in_channels;
             int matched_channels, extra_channels;
-            int score = 0;
+            int score = 100000;
+
+            if (FF_LAYOUT2COUNT(in_chlayout) || FF_LAYOUT2COUNT(out_chlayout)) {
+                /* Compute score in case the input or output layout encodes
+                   a channel count; in this case the score is not altered by
+                   the computation afterwards, as in_chlayout and
+                   out_chlayout have both been set to 0 */
+                if (FF_LAYOUT2COUNT(in_chlayout))
+                    in_channels = FF_LAYOUT2COUNT(in_chlayout);
+                if (FF_LAYOUT2COUNT(out_chlayout))
+                    out_channels = FF_LAYOUT2COUNT(out_chlayout);
+                score -= 10000 + FFABS(out_channels - in_channels) +
+                         (in_channels > out_channels ? 10000 : 0);
+                in_chlayout = out_chlayout = 0;
+                /* Let the remaining computation run, even if the score
+                   value is not altered */
+            }
 
             /* channel substitution */
             for (k = 0; k < FF_ARRAY_ELEMS(ch_subst); k++) {

libavfilter/formats.c

@@ -19,6 +19,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/avassert.h"
 #include "libavutil/channel_layout.h"
 #include "libavutil/common.h"
 #include "libavutil/eval.h"
@@ -28,6 +29,8 @@
 #include "internal.h"
 #include "formats.h"
 
+#define KNOWN(l) (!FF_LAYOUT2COUNT(l)) /* for readability */
+
 /**
  * Add all refs from a to ret and destroy a.
  */
@@ -136,21 +139,77 @@ AVFilterChannelLayouts *ff_merge_channel_layouts(AVFilterChannelLayouts *a,
                                                  AVFilterChannelLayouts *b)
 {
     AVFilterChannelLayouts *ret = NULL;
+    unsigned a_all = a->all_layouts + a->all_counts;
+    unsigned b_all = b->all_layouts + b->all_counts;
+    int ret_max, ret_nb = 0, i, j, round;
 
     if (a == b) return a;
 
-    if (a->nb_channel_layouts && b->nb_channel_layouts) {
-        MERGE_FORMATS(ret, a, b, channel_layouts, nb_channel_layouts,
-                      AVFilterChannelLayouts, fail);
-    } else if (a->nb_channel_layouts) {
-        MERGE_REF(a, b, channel_layouts, AVFilterChannelLayouts, fail);
-        ret = a;
-    } else {
+    /* Put the most generic set in a, to avoid doing everything twice */
+    if (a_all < b_all) {
+        FFSWAP(AVFilterChannelLayouts *, a, b);
+        FFSWAP(unsigned, a_all, b_all);
+    }
+    if (a_all) {
+        if (a_all == 1 && !b_all) {
+            /* keep only known layouts in b; works also for b_all = 1 */
+            for (i = j = 0; i < b->nb_channel_layouts; i++)
+                if (KNOWN(b->channel_layouts[i]))
+                    b->channel_layouts[j++] = b->channel_layouts[i];
+            b->nb_channel_layouts = j;
+        }
         MERGE_REF(b, a, channel_layouts, AVFilterChannelLayouts, fail);
-        ret = b;
+        return b;
     }
 
+    ret_max = a->nb_channel_layouts + b->nb_channel_layouts;
+    if (!(ret = av_mallocz(sizeof(*ret))) ||
+        !(ret->channel_layouts = av_malloc(sizeof(*ret->channel_layouts) *
+                                           ret_max)))
+        goto fail;
+
+    /* a[known] intersect b[known] */
+    for (i = 0; i < a->nb_channel_layouts; i++) {
+        if (!KNOWN(a->channel_layouts[i]))
+            continue;
+        for (j = 0; j < b->nb_channel_layouts; j++) {
+            if (a->channel_layouts[i] == b->channel_layouts[j]) {
+                ret->channel_layouts[ret_nb++] = a->channel_layouts[i];
+                a->channel_layouts[i] = b->channel_layouts[j] = 0;
+            }
+        }
+    }
+    /* 1st round: a[known] intersect b[generic]
+       2nd round: a[generic] intersect b[known] */
+    for (round = 0; round < 2; round++) {
+        for (i = 0; i < a->nb_channel_layouts; i++) {
+            uint64_t fmt = a->channel_layouts[i], bfmt;
+            if (!fmt || !KNOWN(fmt))
+                continue;
+            bfmt = FF_COUNT2LAYOUT(av_get_channel_layout_nb_channels(fmt));
+            for (j = 0; j < b->nb_channel_layouts; j++)
+                if (b->channel_layouts[j] == bfmt)
+                    ret->channel_layouts[ret_nb++] = a->channel_layouts[i];
+        }
+        /* 1st round: swap to prepare 2nd round; 2nd round: put it back */
+        FFSWAP(AVFilterChannelLayouts *, a, b);
+    }
+    /* a[generic] intersect b[generic] */
+    for (i = 0; i < a->nb_channel_layouts; i++) {
+        if (KNOWN(a->channel_layouts[i]))
+            continue;
+        for (j = 0; j < b->nb_channel_layouts; j++)
+            if (a->channel_layouts[i] == b->channel_layouts[j])
+                ret->channel_layouts[ret_nb++] = a->channel_layouts[i];
+    }
+
+    ret->nb_channel_layouts = ret_nb;
+    if (!ret->nb_channel_layouts)
+        goto fail;
+    MERGE_REF(ret, a, channel_layouts, AVFilterChannelLayouts, fail);
+    MERGE_REF(ret, b, channel_layouts, AVFilterChannelLayouts, fail);
     return ret;
+
 fail:
     if (ret) {
         av_freep(&ret->refs);
@@ -248,17 +307,19 @@ do {                                                        \
                                                             \
     (*f)->list = fmts;                                      \
     (*f)->list[(*f)->nb++] = fmt;                           \
-    return 0;                                               \
 } while (0)
 
 int ff_add_format(AVFilterFormats **avff, int64_t fmt)
 {
     ADD_FORMAT(avff, fmt, int, formats, format_count);
+    return 0;
 }
 
 int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout)
 {
+    av_assert1(!(*l && (*l)->all_layouts));
     ADD_FORMAT(l, channel_layout, uint64_t, channel_layouts, nb_channel_layouts);
+    return 0;
 }
 
 AVFilterFormats *ff_all_formats(enum AVMediaType type)
@@ -309,6 +370,9 @@ AVFilterFormats *ff_all_samplerates(void)
 AVFilterChannelLayouts *ff_all_channel_layouts(void)
 {
     AVFilterChannelLayouts *ret = av_mallocz(sizeof(*ret));
+    if (!ret)
+        return NULL;
+    ret->all_layouts = 1;
     return ret;
 }
 

libavfilter/formats.h

@@ -69,14 +69,45 @@ struct AVFilterFormats {
     struct AVFilterFormats ***refs; ///< references to this list
 };
 
+/**
+ * A list of supported channel layouts.
+ *
+ * The list works the same as AVFilterFormats, except for the following
+ * differences:
+ * - A list with all_layouts = 1 means all channel layouts with a known
+ *   disposition; nb_channel_layouts must then be 0.
+ * - A list with all_counts = 1 means all channel counts, with a known or
+ *   unknown disposition; nb_channel_layouts must then be 0 and all_layouts 1.
+ * - The list must not contain a layout with a known disposition and a
+ *   channel count with unknown disposition with the same number of channels
+ *   (e.g. AV_CH_LAYOUT_STEREO and FF_COUNT2LAYOUT(2).
+ */
 typedef struct AVFilterChannelLayouts {
     uint64_t *channel_layouts;  ///< list of channel layouts
     int    nb_channel_layouts;  ///< number of channel layouts
+    char all_layouts;           ///< accept any known channel layout
+    char all_counts;            ///< accept any channel layout or count
 
     unsigned refcount;          ///< number of references to this list
     struct AVFilterChannelLayouts ***refs; ///< references to this list
 } AVFilterChannelLayouts;
 
+/**
+ * Encode a channel count as a channel layout.
+ * FF_COUNT2LAYOUT(c) means any channel layout with c channels, with a known
+ * or unknown disposition.
+ * The result is only valid inside AVFilterChannelLayouts and immediately
+ * related functions.
+ */
+#define FF_COUNT2LAYOUT(c) (0x8000000000000000ULL | (c))
+
+/**
+ * Decode a channel count encoded as a channel layout.
+ * Return 0 if the channel layout was a real one.
+ */
+#define FF_LAYOUT2COUNT(l) (((l) & 0x8000000000000000ULL) ? \
+                           (int)((l) & 0x7FFFFFFF) : 0)
+
 /**
  * Return a channel layouts/samplerates list which contains the intersection of
  * the layouts/samplerates of a and b. Also, all the references of a, all the