vpxenc: Move config check code into its own source files.

- Add command line args that allow display of warnings without prompting
  for user input.
- Extend warning code to make it somewhat scalable.

Change-Id: I2bad8f9315f6eed120c2e1bbe0a2a5ede15fbf35

examples.mk

@@ -41,6 +41,7 @@ vpxenc.SRCS                 += args.c args.h y4minput.c y4minput.h vpxenc.h
 vpxenc.SRCS                 += ivfdec.c ivfdec.h
 vpxenc.SRCS                 += ivfenc.c ivfenc.h
 vpxenc.SRCS                 += tools_common.c tools_common.h
+vpxenc.SRCS                 += warnings.c warnings.h
 vpxenc.SRCS                 += webmenc.c webmenc.h
 vpxenc.SRCS                 += vpx_ports/mem_ops.h
 vpxenc.SRCS                 += vpx_ports/mem_ops_aligned.h

vpxenc.c

@@ -40,6 +40,7 @@
 #include "vpx_ports/mem_ops.h"
 #include "vpx_ports/vpx_timer.h"
 #include "./vpxstats.h"
+#include "./warnings.h"
 #include "./webmenc.h"
 #include "./y4minput.h"
 
@@ -238,13 +239,16 @@ static const arg_def_t rate_hist_n         = ARG_DEF(NULL, "rate-hist", 1,
 static const arg_def_t disable_warnings =
     ARG_DEF(NULL, "disable-warnings", 0,
             "Disable warnings about potentially incorrect encode settings.");
+static const arg_def_t disable_warning_prompt =
+    ARG_DEF("y", "disable-warning-prompt", 0,
+            "Display warnings, but do not prompt user to continue.");
 
 static const arg_def_t *main_args[] = {
   &debugmode,
   &outputfile, &codecarg, &passes, &pass_arg, &fpf_name, &limit, &skip,
   &deadline, &best_dl, &good_dl, &rt_dl,
   &quietarg, &verbosearg, &psnrarg, &use_ivf, &out_part, &q_hist_n,
-  &rate_hist_n, &disable_warnings,
+  &rate_hist_n, &disable_warnings, &disable_warning_prompt,
   NULL
 };
 
@@ -987,6 +991,10 @@ static void parse_global_config(struct VpxEncoderConfig *global, char **argv) {
       global->show_q_hist_buckets = arg_parse_uint(&arg);
     else if (arg_match(&arg, &rate_hist_n, argi))
       global->show_rate_hist_buckets = arg_parse_uint(&arg);
+    else if (arg_match(&arg, &disable_warnings, argi))
+      global->disable_warnings = 1;
+    else if (arg_match(&arg, &disable_warning_prompt, argi))
+      global->disable_warning_prompt = 1;
     else
       argj++;
   }
@@ -1259,7 +1267,7 @@ static int parse_stream_params(struct VpxEncoderConfig *global,
 #define FOREACH_STREAM(func) \
   do { \
     struct stream_state *stream; \
-    for(stream = streams; stream; stream = stream->next) { \
+    for (stream = streams; stream; stream = stream->next) { \
       func; \
     } \
   } while (0)
@@ -1729,31 +1737,6 @@ static void print_time(const char *label, int64_t etl) {
   }
 }
 
-int continue_prompt() {
-  int c;
-  fprintf(stderr, "Continue? (y to continue) ");
-  c = getchar();
-  return c == 'y';
-}
-
-void check_quantizer(struct VpxEncoderConfig* config, int min_q, int max_q) {
-  int check_failed = 0;
-
-  if (config->disable_warnings)
-    return;
-
-  if (min_q == max_q || abs(max_q - min_q) < 8) {
-    check_failed = 1;
-  }
-
-  if (check_failed) {
-    warn("Bad quantizer values. Quantizer values must not be equal, and "
-         "should differ by at least 8.");
-
-    if (!continue_prompt())
-      exit(EXIT_FAILURE);
-  }
-}
 
 int main(int argc, const char **argv_) {
   int pass;
@@ -1807,10 +1790,9 @@ int main(int argc, const char **argv_) {
     if (argi[0][0] == '-' && argi[0][1])
       die("Error: Unrecognized option %s\n", *argi);
 
-  FOREACH_STREAM(
-      check_quantizer(&global,
-                      stream->config.cfg.rc_min_quantizer,
-                      stream->config.cfg.rc_max_quantizer););
+  FOREACH_STREAM(check_encoder_config(global.disable_warning_prompt,
+                                      &global, &stream->config.cfg););
+
   /* Handle non-option arguments */
   input.filename = argv[0];
 

warnings.c

@@ -0,0 +1,116 @@
+/*
+ *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "./warnings.h"
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vpx/vpx_encoder.h"
+
+#include "./tools_common.h"
+#include "./vpxenc.h"
+
+static const char quantizer_warning_string[] =
+    "Bad quantizer values. Quantizer values should not be equal, and should "
+    "differ by at least 8.";
+static const char lag_in_frames_with_realtime[] =
+    "Lag in frames is ignored when deadline is set to realtime.";
+
+struct WarningListNode {
+  const char *warning_string;
+  struct WarningListNode *next_warning;
+};
+
+struct WarningList {
+  struct WarningListNode *warning_node;
+};
+
+static void add_warning(const char *warning_string,
+                        struct WarningList *warning_list) {
+  struct WarningListNode **node = &warning_list->warning_node;
+
+  struct WarningListNode *new_node = malloc(sizeof(*new_node));
+  if (new_node == NULL) {
+    fatal("Unable to allocate warning node.");
+  }
+
+  new_node->warning_string = warning_string;
+  new_node->next_warning = NULL;
+
+  while (*node != NULL)
+    node = &(*node)->next_warning;
+
+  *node = new_node;
+}
+
+static void free_warning_list(struct WarningList *warning_list) {
+  struct WarningListNode *node = warning_list->warning_node;
+  while (warning_list->warning_node != NULL) {
+    node = warning_list->warning_node->next_warning;
+    free(warning_list->warning_node);
+    warning_list->warning_node = node;
+  }
+}
+
+static int continue_prompt(int num_warnings) {
+  int c;
+  fprintf(stderr,
+          "%d encoder configuration warning(s). Continue? (y to continue) ",
+          num_warnings);
+  c = getchar();
+  return c == 'y';
+}
+
+static void check_lag_in_frames_realtime_deadline(
+    int lag_in_frames,
+    int deadline,
+    struct WarningList *warning_list) {
+  if (deadline == VPX_DL_REALTIME && lag_in_frames != 0)
+    add_warning(lag_in_frames_with_realtime, warning_list);
+}
+
+static void check_quantizer(int min_q, int max_q,
+                            struct WarningList *warning_list) {
+  if (min_q == max_q || abs(max_q - min_q) < 8)
+    add_warning(quantizer_warning_string, warning_list);
+}
+
+void check_encoder_config(int disable_prompt,
+                          const struct VpxEncoderConfig *global_config,
+                          const struct vpx_codec_enc_cfg *stream_config) {
+  int num_warnings = 0;
+  struct WarningListNode *warning = NULL;
+  struct WarningList warning_list = {0};
+
+  check_quantizer(stream_config->rc_min_quantizer,
+                  stream_config->rc_max_quantizer,
+                  &warning_list);
+  check_lag_in_frames_realtime_deadline(stream_config->g_lag_in_frames,
+                                        global_config->deadline,
+                                        &warning_list);
+
+  /* Count and print warnings. */
+  for (warning = warning_list.warning_node;
+       warning != NULL;
+       warning = warning->next_warning,
+       ++num_warnings) {
+    warn(warning->warning_string);
+  }
+
+  free_warning_list(&warning_list);
+
+  if (num_warnings) {
+    if (!disable_prompt && !continue_prompt(num_warnings))
+      exit(EXIT_FAILURE);
+  }
+}

warnings.h

@@ -0,0 +1,25 @@
+/*
+ *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef WARNINGS_H_
+#define WARNINGS_H_
+
+struct vpx_codec_enc_cfg;
+struct VpxEncoderConfig;
+
+/*
+ * Checks config for improperly used settings. Warns user upon encountering
+ * settings that will lead to poor output quality. Prompts user to continue
+ * when warnings are issued.
+ */
+void check_encoder_config(int disable_prompt,
+                          const struct VpxEncoderConfig *global_config,
+                          const struct vpx_codec_enc_cfg *stream_config);
+
+#endif  // WARNINGS_H_