ffprobe: report bit rate in stream description

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

doc/ffprobe.xsd

@@ -110,6 +110,7 @@
       <xsd:attribute name="time_base"        type="xsd:string" use="required"/>
       <xsd:attribute name="start_time"       type="xsd:float"/>
       <xsd:attribute name="duration"         type="xsd:float"/>
+      <xsd:attribute name="bit_rate"         type="xsd:int"/>
       <xsd:attribute name="nb_frames"        type="xsd:int"/>
       <xsd:attribute name="nb_read_frames"   type="xsd:int"/>
       <xsd:attribute name="nb_read_packets"  type="xsd:int"/>

ffprobe.c

@@ -1509,6 +1509,8 @@ static void show_stream(WriterContext *w, AVFormatContext *fmt_ctx, int stream_i
     print_fmt("time_base",      "%d/%d", stream->time_base.num,      stream->time_base.den);
     print_time("start_time",    stream->start_time, &stream->time_base);
     print_time("duration",      stream->duration,   &stream->time_base);
+    if (dec_ctx->bit_rate > 0) print_val    ("bit_rate", dec_ctx->bit_rate, unit_bit_per_second_str);
+    else                       print_str_opt("bit_rate", "N/A");
     if (stream->nb_frames) print_fmt    ("nb_frames", "%"PRId64, stream->nb_frames);
     else                   print_str_opt("nb_frames", "N/A");
     if (nb_streams_frames[stream_idx])  print_fmt    ("nb_read_frames", "%"PRIu64, nb_streams_frames[stream_idx]);