MMAL: Fix example_basic_2 to actually play video

example_basic_2 seemed to be broken. It tried to use
ZERO_COPY but in an invalid way. It also never looked
for format changed events off the decoder, so would
just stop once the decoder issued those.

It now correctly allocates pools so that it can use zero
copy, and also acts on MMAL_EVENT_FORMAT_CHANGED events
to reallocate the pools and hence proceed.

Fixes #285

diff --git a/interface/mmal/test/examples/example_basic_2.c b/interface/mmal/test/examples/example_basic_2.c
index 096a0792a18787d2b473dc06bd8a751f3ceb398d..cc474f26824d5f3643c62ece89795b74cb14da73 100644 (file)
--- a/interface/mmal/test/examples/example_basic_2.c
+++ b/interface/mmal/test/examples/example_basic_2.c
@@ -29,6 +29,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "mmal.h"
 #include "util/mmal_default_components.h"
 #include "util/mmal_util_params.h"
+#include "util/mmal_util.h"
 #include "interface/vcos/vcos.h"
 #include <stdio.h>
 
@@ -57,6 +58,18 @@ static struct CONTEXT_T {
    MMAL_STATUS_T status;
 } context;
 
+static void log_video_format(MMAL_ES_FORMAT_T *format)
+{
+   if (format->type != MMAL_ES_TYPE_VIDEO)
+      return;
+
+   fprintf(stderr, "fourcc: %4.4s, width: %i, height: %i, (%i,%i,%i,%i)\n",
+            (char *)&format->encoding,
+            format->es->video.width, format->es->video.height,
+            format->es->video.crop.x, format->es->video.crop.y,
+            format->es->video.crop.width, format->es->video.crop.height);
+}
+
 /** Callback from the control port.
  * Component is sending us an event. */
 static void control_callback(MMAL_PORT_T *port, MMAL_BUFFER_HEADER_T *buffer)
@@ -204,10 +217,12 @@ int main(int argc, char **argv)
    decoder->input[0]->buffer_size = decoder->input[0]->buffer_size_min;
    decoder->output[0]->buffer_num = decoder->output[0]->buffer_num_min;
    decoder->output[0]->buffer_size = decoder->output[0]->buffer_size_min;
-   pool_in = mmal_pool_create(decoder->input[0]->buffer_num,
-                              decoder->input[0]->buffer_size);
-   pool_out = mmal_pool_create(decoder->output[0]->buffer_num,
-                               decoder->output[0]->buffer_size);
+   pool_in = mmal_port_pool_create(decoder->output[0],
+                                   decoder->input[0]->buffer_num,
+                                   decoder->input[0]->buffer_size);
+   pool_out = mmal_port_pool_create(decoder->output[0],
+                                    decoder->output[0]->buffer_num,
+                                    decoder->output[0]->buffer_size);
 
    /* Create a queue to store our decoded video frames. The callback we will get when
     * a frame has been decoded will put the frame into this queue. */
@@ -242,7 +257,10 @@ int main(int argc, char **argv)
 
       /* Check for errors */
       if (context.status != MMAL_SUCCESS)
+      {
+         fprintf(stderr, "Aborting due to error\n");
          break;
+      }
 
       /* Send data to decode to the input port of the video decoder */
       if (!eos_sent && (buffer = mmal_queue_get(pool_in->queue)) != NULL)
@@ -267,7 +285,57 @@ int main(int argc, char **argv)
          eos_received = buffer->flags & MMAL_BUFFER_HEADER_FLAG_EOS;
 
          if (buffer->cmd)
-            fprintf(stderr, "received event %4.4s", (char *)&buffer->cmd);
+         {
+            fprintf(stderr, "received event %4.4s\n", (char *)&buffer->cmd);
+            if (buffer->cmd == MMAL_EVENT_FORMAT_CHANGED)
+            {
+               MMAL_EVENT_FORMAT_CHANGED_T *event = mmal_event_format_changed_get(buffer);
+               if (event)
+               {
+                  fprintf(stderr, "----------Port format changed----------\n");
+                  log_video_format(decoder->output[0]->format);
+                  fprintf(stderr, "-----------------to---------------------\n");
+                  log_video_format(event->format);
+                  fprintf(stderr, " buffers num (opt %i, min %i), size (opt %i, min: %i)\n",
+                           event->buffer_num_recommended, event->buffer_num_min,
+                           event->buffer_size_recommended, event->buffer_size_min);
+                  fprintf(stderr, "----------------------------------------\n");
+               }
+
+               //Assume we can't reuse the buffers, so have to disable, destroy
+               //pool, create new pool, enable port, feed in buffers.
+               status = mmal_port_disable(decoder->output[0]);
+               CHECK_STATUS(status, "failed to disable port");
+
+               //Clear the queue of all buffers
+               while(mmal_queue_length(pool_out->queue) != pool_out->headers_num)
+               {
+                  MMAL_BUFFER_HEADER_T *buf;
+                  fprintf(stderr, "Wait for buffers to be returned. Have %d of %d buffers\n",
+                        mmal_queue_length(pool_out->queue), pool_out->headers_num);
+                  vcos_semaphore_wait(&context.semaphore);
+                  fprintf(stderr, "Got semaphore\n");
+                  buf = mmal_queue_get(context.queue);
+                  mmal_buffer_header_release(buf);
+               }
+               fprintf(stderr, "Got all buffers\n");
+
+               mmal_port_pool_destroy(decoder->output[0], pool_out);
+               status = mmal_format_full_copy(decoder->output[0]->format, event->format);
+               CHECK_STATUS(status, "failed to copy port format");
+               status = mmal_port_format_commit(decoder->output[0]);
+               CHECK_STATUS(status, "failed to commit port format");
+
+               pool_out = mmal_port_pool_create(decoder->output[0],
+                                    decoder->output[0]->buffer_num,
+                                    decoder->output[0]->buffer_size);
+
+               status = mmal_port_enable(decoder->output[0], output_callback);
+               CHECK_STATUS(status, "failed to enable port");
+               //Allow the following loop to send all the buffers back to the decoder
+            }
+
+         }
          else
             fprintf(stderr, "decoded frame (flags %x)\n", buffer->flags);
          mmal_buffer_header_release(buffer);
@@ -279,10 +347,10 @@ int main(int argc, char **argv)
          status = mmal_port_send_buffer(decoder->output[0], buffer);
          CHECK_STATUS(status, "failed to send buffer");
       }
-}
+   }
 
    /* Stop decoding */
-   fprintf(stderr, "stop decoding\n");
+   fprintf(stderr, "stop decoding - count %d, eos_received %d\n", count, eos_received);
 
    /* Stop everything. Not strictly necessary since mmal_component_destroy()
     * will do that anyway */
@@ -292,12 +360,12 @@ int main(int argc, char **argv)
 
  error:
    /* Cleanup everything */
-   if (decoder)
-      mmal_component_destroy(decoder);
    if (pool_in)
-      mmal_pool_destroy(pool_in);
+      mmal_port_pool_destroy(decoder->input[0], pool_in);
    if (pool_out)
-      mmal_pool_destroy(pool_out);
+      mmal_port_pool_destroy(decoder->output[0], pool_out);
+   if (decoder)
+      mmal_component_destroy(decoder);
    if (context.queue)
       mmal_queue_destroy(context.queue);