vpx[dec|enc]: Extract IVF support from the apps.

- Move IVF reading support into ivfdec.c and ivfdec.h
- Move IVF writing support into ivfenc.c and ivfenc.h
- Removed IVF writing code from the SVC example in favor of ivfenc.

Change-Id: I70adf6240d0320fdd232d8546ed573f0f68dd793

tools_common.c

@@ -7,10 +7,13 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
+
 #include "tools_common.h"
 
 #include <stdarg.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #if defined(_WIN32) || defined(__OS2__)
 #include <io.h>
@@ -56,3 +59,74 @@ void fatal(const char *fmt, ...) {
 void warn(const char *fmt, ...) {
   LOG_ERROR("Warning");
 }
+
+uint16_t mem_get_le16(const void *data) {
+  uint16_t val;
+  const uint8_t *mem = (const uint8_t*)data;
+
+  val = mem[1] << 8;
+  val |= mem[0];
+  return val;
+}
+
+uint32_t mem_get_le32(const void *data) {
+  uint32_t val;
+  const uint8_t *mem = (const uint8_t*)data;
+
+  val = mem[3] << 24;
+  val |= mem[2] << 16;
+  val |= mem[1] << 8;
+  val |= mem[0];
+  return val;
+}
+
+int read_yuv_frame(struct VpxInputContext *input_ctx, vpx_image_t *yuv_frame) {
+  FILE *f = input_ctx->file;
+  struct FileTypeDetectionBuffer *detect = &input_ctx->detect;
+  int plane = 0;
+  int shortread = 0;
+
+  for (plane = 0; plane < 3; ++plane) {
+    uint8_t *ptr;
+    const int w = (plane ? (1 + yuv_frame->d_w) / 2 : yuv_frame->d_w);
+    const int h = (plane ? (1 + yuv_frame->d_h) / 2 : yuv_frame->d_h);
+    int r;
+
+    /* Determine the correct plane based on the image format. The for-loop
+     * always counts in Y,U,V order, but this may not match the order of
+     * the data on disk.
+     */
+    switch (plane) {
+      case 1:
+        ptr = yuv_frame->planes[
+            yuv_frame->fmt == VPX_IMG_FMT_YV12 ? VPX_PLANE_V : VPX_PLANE_U];
+        break;
+      case 2:
+        ptr = yuv_frame->planes[
+            yuv_frame->fmt == VPX_IMG_FMT_YV12 ? VPX_PLANE_U : VPX_PLANE_V];
+        break;
+      default:
+        ptr = yuv_frame->planes[plane];
+    }
+
+    for (r = 0; r < h; ++r) {
+      size_t needed = w;
+      size_t buf_position = 0;
+      const size_t left = detect->buf_read - detect->position;
+      if (left > 0) {
+        const size_t more = (left < needed) ? left : needed;
+        memcpy(ptr, detect->buf + detect->position, more);
+        buf_position = more;
+        needed -= more;
+        detect->position += more;
+      }
+      if (needed > 0) {
+        shortread |= (fread(ptr + buf_position, 1, needed, f) < needed);
+      }
+
+      ptr += yuv_frame->stride[plane];
+    }
+  }
+
+  return shortread;
+}