y4m start header parsing ready

src/cfg.c

@@ -163,6 +163,8 @@ int kvz_config_init(kvz_config *cfg)
   cfg->intra_bit_allocation = false;
   cfg->clip_neighbour = true;
 
+  cfg->file_format = KVZ_FORMAT_AUTO;
+
   return 1;
 }
 
@@ -448,8 +450,10 @@ int kvz_config_parse(kvz_config *cfg, const char *name, const char *value)
   static const char * const scaling_list_names[] = { "off", "custom", "default", NULL };
 
   static const char * const rc_algorithm_names[] = { "no-rc", "lambda", "oba", NULL };
-  static const char * const preset_values[11][25*2] = {
 
+  static const char * const file_format_names[] = {"y4m", NULL};
+
+  static const char * const preset_values[11][25*2] = {
       {
         "ultrafast",
         "rd", "0",
@@ -1359,6 +1363,15 @@ int kvz_config_parse(kvz_config *cfg, const char *name, const char *value)
   else if OPT("clip-neighbour") {
     cfg->clip_neighbour = atobool(value);
   }
+  else if OPT("input-file-format") {
+    int8_t file_format = 0;
+    if (!parse_enum(value, file_format_names, &file_format)) {
+      fprintf(stderr, "Invalid input file format %s. Valid values include %s\n", value,
+        file_format_names[0]);
+      return 0;
+    }
+    cfg->file_format = file_format;
+  }
   else {
     return 0;
   }

src/cli.c

@@ -149,6 +149,7 @@ static const struct option long_options[] = {
   { "no-intra-bits",            no_argument, NULL, 0 },
   { "clip-neighbour",           no_argument, NULL, 0 },
   { "no-clip-neighbour",        no_argument, NULL, 0 },
+  { "input-file-format",  required_argument, NULL, 0 },
   {0, 0, 0, 0}
 };
 
@@ -184,6 +185,26 @@ static int select_input_res_auto(const char *file_name, int32_t *out_width, int3
   return success;
 }
 
+/**
+* \brief Try to detect file format from file name automatically
+*
+* \param file_name    file name to get format from
+* \return      0 (auto) if no format is detected, or id of the format
+*/
+static int detect_file_format(const char *file_name) {
+  if (!file_name) return 0;
+
+  // Find the last delimiter char ( / or \ ). Hope the other kind is not used in the name.
+  // If delim is not found, set pointer to the beginning.
+  unsigned char* sub_str = (unsigned char*)strrchr(file_name, '.');
+  if (!sub_str) return 0;
+
+  // KVZ_FILE_FORMAT
+  if (strcmp(sub_str, ".y4m") == 0) return 1;
+
+  return 0;
+}
+
 /**
  * \brief Parse command line arguments.
  * \param argc  Number of arguments
@@ -289,8 +310,13 @@ cmdline_opts_t* cmdline_opts_parse(const kvz_api *const api, int argc, char *arg
     goto done;
   }
 
+  // Check the file name for format
+  if (opts->config->file_format == KVZ_FORMAT_AUTO) {
+    opts->config->file_format = detect_file_format(opts->input);
+  }
+
   // Set resolution automatically if necessary
-  if (opts->config->width == 0 && opts->config->height == 0) {
+  if (opts->config->file_format == KVZ_FORMAT_AUTO && opts->config->width == 0 && opts->config->height == 0) {
     ok = select_input_res_auto(opts->input, &opts->config->width, &opts->config->height);
     goto done;
   }
@@ -370,6 +396,9 @@ void print_help(void)
     "      --input-format <string> : P420 or P400 [P420]\n"
     "      --input-bitdepth <int> : 8-16 [8]\n"
     "      --loop-input           : Re-read input file forever.\n"
+    "      --input-file-format <string> : Input file format if other than RAW [auto]\n"
+    "                                    - auto: Check the file ending for format\n"
+    "                                    - y4m\n"
     "\n"
     /* Word wrap to this width to stay under 80 characters (including ") *************/
     "Options:\n"

src/encmain.c

@@ -310,6 +310,92 @@ static double calc_avg_qp(uint64_t qp_sum, uint32_t frames_done)
   return (double)qp_sum / (double)frames_done;
 }
 
+/**
+* \brief Reads the information in y4m header
+*
+* \param input  Pointer to the input file
+* \param config Pointer to the config struct
+*/
+static bool read_header(FILE* input, kvz_config* config) {
+  char buffer[256];
+  bool end_of_header = false;
+
+  while(!end_of_header) {
+    for (int i = 0; i < 256; i++) {
+      buffer[i] = getc(input);
+      // Start code of frame data
+      if (buffer[i] == 0x0A) {
+        for (; i > 0; i--) {
+          ungetc(buffer[i], input);
+        }
+        end_of_header = true;
+        break;
+      }
+      // Header sections are separated by space (ascii 0x20)
+      if (buffer[i] == 0x20) {
+        // Header start sequence does not hold any addition information, so it can be skipped
+        if ((i == 9) && strncmp(buffer, "YUV4MPEG2 ", 10) == 0) {
+          break;
+        }
+        switch (buffer[0]) {
+        // Width
+        case 'W':
+          // Exclude starting 'W' and the space at the end with substr
+          config->width = atoi(&buffer[1]);
+          break;
+        // Height
+        case 'H':
+          // Exclude starting 'H' and the space at the end with substr
+          config->height = atoi(&buffer[1]);
+          break;
+        // Framerate (or start code of frame)
+        case 'F':
+          // The header has no ending signature other than the start code of a frame
+          if (i > 5 && strncmp(buffer, "FRAME", 5) == 0) {
+            for (; i > 0; i--) {
+              ungetc(buffer[i], input);
+            }
+            end_of_header = true;
+            break;
+          }
+          else {
+            config->framerate_num = atoi(&buffer[1]);
+            for (int j = 0; j < i; j++) {
+              if (buffer[j] == ':') {
+                config->framerate_denom = atoi(&buffer[j + 1]);
+              }
+            }
+            break;
+          }
+        // Interlacing
+        case 'I':
+          break;
+        // Aspect ratio
+        case 'A':
+          break;
+        // Colour space
+        case 'C':
+          break;
+        // Comment
+        case 'X':
+          break;
+        default:
+          fprintf(stderr, "Unknown header argument starting with '%i'\n", buffer[0]);
+          break;
+        }
+        break;
+      }
+    }
+  }
+
+  if (config->width == 0 || config->height == 0 || config->framerate_num == 0 || config->framerate_denom == 0) {
+    fprintf(stderr, "Failed to read necessary info from y4m headers. Width, height and frame rate must be present in the headers.\n");
+    return false;
+  }
+
+  return true;
+}
+
 /**
  * \brief Program main function.
  * \param argc Argument count from commandline
@@ -409,6 +495,13 @@ int main(int argc, char *argv[])
     }
   }
 
+  // Parse headers if input data is in y4m container
+  if (opts->config->file_format == KVZ_FORMAT_Y4M) {
+    if (!read_header(input, opts->config)) {
+      goto exit_failure;
+    }
+  }
+
   enc = api->encoder_open(opts->config);
   if (!enc) {
     fprintf(stderr, "Failed to open encoder.\n");

src/kvazaar.h

@@ -227,6 +227,14 @@ enum kvz_rc_algorithm
   KVZ_LAMBDA = 1,
   KVZ_OBA = 2,
 };
+
+enum kvz_file_format
+{
+  KVZ_FORMAT_AUTO = 0,
+  KVZ_FORMAT_Y4M = 1
+};
+
+
 // Map from input format to chroma format.
 #define KVZ_FORMAT2CSP(format) ((enum kvz_chroma_format)"\0\1\2\3"[format])
 
@@ -437,6 +445,8 @@ typedef struct kvz_config
   uint8_t intra_bit_allocation;
 
   uint8_t clip_neighbour;
+
+  enum kvz_file_format file_format;
 } kvz_config;
 
 /**