ffmpegdec: Correctly reorder audio channels to the GStreamer order if necessary

ext/ffmpeg/gstffmpegcodecmap.c

@@ -102,46 +102,52 @@ static const struct
   CH_STEREO_RIGHT, GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT}
 };
 
-static gboolean
+gboolean
-gst_ff_channel_layout_to_gst (guint64 channel_layout, guint channels,
+gst_ffmpeg_channel_layout_to_gst (AVCodecContext * context,
     GstAudioChannelPosition * pos)
 {
-  guint nchannels = 0, i, j;
+  guint nchannels = 0, channels = context->channels;
+  guint64 channel_layout = context->channel_layout;
   gboolean none_layout = FALSE;
 
-  for (i = 0; i < 64; i++) {
-    if ((channel_layout & (G_GUINT64_CONSTANT (1) << i)) != 0) {
-      nchannels++;
-    }
-  }
-
   if (channel_layout == 0) {
     nchannels = channels;
     none_layout = TRUE;
-  }
+  } else {
+    guint i, j;
 
-  if (nchannels != channels) {
+    for (i = 0; i < 64; i++) {
-    GST_ERROR ("Number of channels is different (%u != %u)", channels,
+      if ((channel_layout & (G_GUINT64_CONSTANT (1) << i)) != 0) {
-        nchannels);
+        nchannels++;
-    return FALSE;
+      }
-  }
+    }
 
-  for (i = 0, j = 0; i < G_N_ELEMENTS (_ff_to_gst_layout); i++) {
+    if (nchannels != channels) {
-    if ((channel_layout & _ff_to_gst_layout[i].ff) != 0) {
+      GST_ERROR ("Number of channels is different (%u != %u)", channels,
-      pos[j++] = _ff_to_gst_layout[i].gst;
+          nchannels);
+      nchannels = channels;
+      none_layout = TRUE;
+    } else {
 
-      if (_ff_to_gst_layout[i].gst == GST_AUDIO_CHANNEL_POSITION_NONE)
+      for (i = 0, j = 0; i < G_N_ELEMENTS (_ff_to_gst_layout); i++) {
+        if ((channel_layout & _ff_to_gst_layout[i].ff) != 0) {
+          pos[j++] = _ff_to_gst_layout[i].gst;
+
+          if (_ff_to_gst_layout[i].gst == GST_AUDIO_CHANNEL_POSITION_NONE)
+            none_layout = TRUE;
+        }
+      }
+
+      if (j != nchannels) {
+        GST_WARNING
+            ("Unknown channels in channel layout - assuming NONE layout");
         none_layout = TRUE;
+      }
     }
   }
 
-  if (j != nchannels) {
-    GST_WARNING ("Unknown channels in channel layout - assuming NONE layout");
-    none_layout = TRUE;
-  }
-
   if (!none_layout
-      && !gst_audio_check_valid_channel_positions (pos, nchannels, TRUE)) {
+      && !gst_audio_check_valid_channel_positions (pos, nchannels, FALSE)) {
     GST_ERROR ("Invalid channel layout %" G_GUINT64_FORMAT
         " - assuming NONE layout", channel_layout);
     none_layout = TRUE;
@@ -153,9 +159,9 @@ gst_ff_channel_layout_to_gst (guint64 channel_layout, guint channels,
     } else if (nchannels == 2) {
       pos[0] = GST_AUDIO_CHANNEL_POSITION_FRONT_LEFT;
       pos[1] = GST_AUDIO_CHANNEL_POSITION_FRONT_RIGHT;
-    } else if (channel_layout == 0) {
-      return FALSE;
     } else {
+      guint i;
+
       for (i = 0; i < nchannels; i++)
         pos[i] = GST_AUDIO_CHANNEL_POSITION_NONE;
     }
@@ -322,17 +328,13 @@ gst_ff_aud_caps_new (AVCodecContext * context, enum CodecID codec_id,
 
   /* fixed, non-probing context */
   if (context != NULL && context->channels != -1) {
-    GstAudioInfo info;
     GstAudioChannelPosition pos[64];
-    guint64 channel_layout = context->channel_layout;
-
-    gst_audio_info_init (&info);
 
     caps = gst_caps_new_simple (mimetype,
         "rate", G_TYPE_INT, context->sample_rate,
         "channels", G_TYPE_INT, context->channels, NULL);
 
-    if (gst_ff_channel_layout_to_gst (channel_layout, context->channels, pos)) {
+    if (gst_ffmpeg_channel_layout_to_gst (context, pos)) {
       guint64 mask;
 
       if (gst_audio_channel_positions_to_mask (pos, context->channels, &mask)) {

ext/ffmpeg/gstffmpegcodecmap.h

@@ -26,7 +26,7 @@
 #include <libavcodec/avcodec.h>
 #endif
 #include <gst/gst.h>
-
+#include <gst/audio/audio.h>
 #include <gst/video/video.h>
 
 /*
@@ -127,5 +127,8 @@ gst_ffmpeg_formatid_get_codecids (const gchar *format_name,
 				  AVOutputFormat * plugin);
 
 
+gboolean
+gst_ffmpeg_channel_layout_to_gst (AVCodecContext * context,
+    GstAudioChannelPosition * pos);
 
 #endif /* __GST_FFMPEG_CODECMAP_H__ */

ext/ffmpeg/gstffmpegdec.c

@@ -97,6 +97,8 @@ struct _GstFFMpegDec
       gint channels;
       gint samplerate;
       gint depth;
+
+      GstAudioChannelPosition ffmpeg_layout[64], gst_layout[64];
     } audio;
   } format;
 
@@ -1350,13 +1352,18 @@ update_audio_context (GstFFMpegDec * ffmpegdec, gboolean force)
 {
   AVCodecContext *context = ffmpegdec->context;
   gint depth;
+  GstAudioChannelPosition pos[64] = { 0, };
 
   depth = av_smp_format_depth (context->sample_fmt);
 
+  gst_ffmpeg_channel_layout_to_gst (context, pos);
+
   if (!force && ffmpegdec->format.audio.samplerate ==
       context->sample_rate &&
       ffmpegdec->format.audio.channels == context->channels &&
-      ffmpegdec->format.audio.depth == depth)
+      ffmpegdec->format.audio.depth == depth &&
+      memcmp (ffmpegdec->format.audio.ffmpeg_layout, pos,
+          sizeof (GstAudioChannelPosition) * context->channels) == 0)
     return FALSE;
 
   GST_DEBUG_OBJECT (ffmpegdec,
@@ -1368,6 +1375,8 @@ update_audio_context (GstFFMpegDec * ffmpegdec, gboolean force)
   ffmpegdec->format.audio.samplerate = context->sample_rate;
   ffmpegdec->format.audio.channels = context->channels;
   ffmpegdec->format.audio.depth = depth;
+  memcpy (ffmpegdec->format.audio.ffmpeg_layout, pos,
+      sizeof (GstAudioChannelPosition) * context->channels);
 
   return TRUE;
 }
@@ -1389,6 +1398,13 @@ gst_ffmpegdec_audio_negotiate (GstFFMpegDec * ffmpegdec, gboolean force)
   if (caps == NULL)
     goto no_caps;
 
+  /* Get GStreamer channel layout */
+  memcpy (ffmpegdec->format.audio.gst_layout,
+      ffmpegdec->format.audio.ffmpeg_layout,
+      sizeof (GstAudioChannelPosition) * ffmpegdec->format.audio.channels);
+  gst_audio_channel_positions_to_valid_order (ffmpegdec->format.
+      audio.gst_layout, ffmpegdec->format.audio.channels);
+
   GST_LOG_OBJECT (ffmpegdec, "output caps %" GST_PTR_FORMAT, caps);
 
   if (!gst_pad_set_caps (ffmpegdec->srcpad, caps))
@@ -2226,7 +2242,19 @@ gst_ffmpegdec_audio_frame (GstFFMpegDec * ffmpegdec,
       "Decode audio: len=%d, have_data=%d", len, have_data);
 
   if (len >= 0 && have_data > 0) {
-    /* FIXME: Reorder here */
+    GstAudioFormat fmt;
+
+    /* Reorder channels to the GStreamer channel order */
+    /* Only the width really matters here... and it's stored as depth */
+    fmt =
+        gst_audio_format_build_integer (TRUE, G_BYTE_ORDER,
+        ffmpegdec->format.audio.depth, ffmpegdec->format.audio.depth);
+
+    gst_audio_reorder_channels (odata, have_data, fmt,
+        ffmpegdec->format.audio.channels,
+        ffmpegdec->format.audio.ffmpeg_layout,
+        ffmpegdec->format.audio.gst_layout);
+
     /* Buffer size */
     gst_buffer_unmap (*outbuf, odata, have_data);