Please describe the problem:
When I run an avi file it fails with errors mentioned. Basically ffmpegcolorspace is returning lesser value then asked by the avidemux. 
The error is due to the condition in gstffmpegcolorspace.c

if (gst_structure_has_field (structure, "palette_data")) {
    *size -= 4 * 256;           /* = AVPALETTE_SIZE */
  }

wherein the palette is considered a part of buffer and hence its value is being subtracted. Basically this is only true for pixel format = PIX_FMT_PAL8, as mentioned in gstffmpegcodecmap.c. But in my case the pixel format is 
PIX_FMT_BGR24 and palette data is not added here, but still its being subtracted. So I would like to suggest to add a condition 

 if (gst_structure_has_field (structure, "palette_data") && ctx->pix_fmt == PIX_FMT_PAL8) {
    *size -= 4 * 256;           /* = AVPALETTE_SIZE */
  }


Steps to reproduce:
1.  GST_DEBUG=2 gst-launch-0.10 filesrc location=waiting.avi ! avidemux ! decodebin ! ffmpegcolorspace ! videoscale ! ximagesink
2.    


Actual results:
** (gst-launch-0.10:24385): WARNING **: ffmpegcsp0: size 11520 is not a multiple of unit size 10496
0:00:00.312994206 24385  0x81462d0 WARN         basetransform gstbasetransform.c:1533:gst_base_transform_handle_buffer:<ffmpegcsp0> error: subclass did not specify output size
0:00:00.313079976 24385  0x81462d0 WARN         basetransform gstbasetransform.c:1533:gst_base_transform_handle_buffer:<ffmpegcsp0> error: subclass did not specify output size
ERROR: from element /pipeline0/ffmpegcsp0: subclass did not specify output size


Expected results:
ffmpegcolorspace should allocate 11520

Does this happen every time?
yes

Other information: