From 907451590ec305adc81f2ab003be378a69dfcc73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Arttu=20Yl=C3=A4-Outinen?= <arttu.yla-outinen@tut.fi>
Date: Tue, 7 Jul 2015 10:05:42 +0300
Subject: [PATCH] Fix encoding when both GOP and OWF are enabled.

Changes kvazaar_encode to not increase cur_state_num unless a frame is
started.
---
 src/encmain.c          | 10 +++++++---
 src/kvazaar.c          | 27 +++++++++++++++++----------
 src/kvazaar_internal.h | 13 +++++++++++++
 3 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/src/encmain.c b/src/encmain.c
index 93d916b3..e1c3e684 100644
--- a/src/encmain.c
+++ b/src/encmain.c
@@ -168,8 +168,6 @@ int main(int argc, char *argv[])
     double psnr_sum[3] = { 0.0, 0.0, 0.0 };
 
     for (;;) {
-      encoder_state_t *state = &enc->states[enc->cur_state_num];
-
       kvz_picture *img_in = NULL;
       if (!feof(input) && (opts->frames == 0 || frames_read < opts->frames)) {
         // Try to read an input frame.
@@ -225,7 +223,13 @@ int main(int argc, char *argv[])
         bitstream_length += len_out;
 
         // Compute and print stats.
-        state = &enc->states[enc->cur_state_num];
+
+        // Number of the state that was finished is one less than
+        // enc->out_state_num.
+        encoder_state_t *state = &enc->states[
+          (enc->out_state_num + enc->num_encoder_states - 1) %
+          enc->num_encoder_states
+        ];
         double frame_psnr[3] = { 0.0, 0.0, 0.0 };
         encoder_compute_stats(state, recout, frame_psnr);
 
diff --git a/src/kvazaar.c b/src/kvazaar.c
index e1f1fd05..e8da06f6 100644
--- a/src/kvazaar.c
+++ b/src/kvazaar.c
@@ -72,6 +72,7 @@ static kvz_encoder * kvazaar_open(const kvz_config *cfg)
 
   encoder->num_encoder_states = encoder->control->owf + 1;
   encoder->cur_state_num = 0;
+  encoder->out_state_num = 0;
   encoder->frames_started = 0;
   encoder->frames_done = 0;
   encoder->states = calloc(encoder->num_encoder_states, sizeof(encoder_state_t));
@@ -141,21 +142,27 @@ static int kvazaar_encode(kvz_encoder *enc,
     return 1;
   }
 
-  // Move to the next encoder state.
-  enc->cur_state_num = (enc->cur_state_num + 1) % (enc->num_encoder_states);
-  state = &enc->states[enc->cur_state_num];
-
   if (!state->frame_done) {
-    threadqueue_waitfor(enc->control->threadqueue, state->tqj_bitstream_written);
+    // We started encoding a frame; move to the next encoder state.
+    enc->cur_state_num = (enc->cur_state_num + 1) % (enc->num_encoder_states);
+  }
+
+  encoder_state_t *output_state = &enc->states[enc->out_state_num];
+  if (!output_state->frame_done &&
+      (pic_in == NULL || enc->cur_state_num == enc->out_state_num)) {
+
+    threadqueue_waitfor(enc->control->threadqueue, output_state->tqj_bitstream_written);
 
     // Get stream length before taking chunks since that clears the stream.
-    if (len_out) *len_out = bitstream_tell(&state->stream) / 8;
-    if (data_out) *data_out = bitstream_take_chunks(&state->stream);
-    if (pic_out) *pic_out = image_copy_ref(state->tile->frame->rec);
+    if (len_out) *len_out = bitstream_tell(&output_state->stream) / 8;
+    if (data_out) *data_out = bitstream_take_chunks(&output_state->stream);
+    if (pic_out) *pic_out = image_copy_ref(output_state->tile->frame->rec);
 
-    state->frame_done = 1;
-    state->prepared = 0;
+    output_state->frame_done = 1;
+    output_state->prepared = 0;
     enc->frames_done += 1;
+
+    enc->out_state_num = (enc->out_state_num + 1) % (enc->num_encoder_states);
   }
 
   return 1;
diff --git a/src/kvazaar_internal.h b/src/kvazaar_internal.h
index 98181b97..fe73825f 100644
--- a/src/kvazaar_internal.h
+++ b/src/kvazaar_internal.h
@@ -30,7 +30,20 @@ struct kvz_encoder {
   struct encoder_control_t* control;
   struct encoder_state_t* states;
   unsigned num_encoder_states;
+
+  /**
+   * \brief Number of the current encoder state.
+   *
+   * The current state is the one that will be used for encoding the frame
+   * that is started next.
+   */
   unsigned cur_state_num;
+
+  /**
+   * \brief Number of the next encoder state to be finished.
+   */
+  unsigned out_state_num;
+
   unsigned frames_started;
   unsigned frames_done;