1 files changed, 112 insertions, 0 deletions
diff --git a/media/libvpx/libvpx/ivfdec.c b/media/libvpx/libvpx/ivfdec.c
new file mode 100644
index 0000000000..3e179bc6ed
--- /dev/null
+++ b/media/libvpx/libvpx/ivfdec.c
@@ -0,0 +1,112 @@
+/*
+ *  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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "vpx_ports/mem_ops.h"
+
+#include "./ivfdec.h"
+
+static const char *IVF_SIGNATURE = "DKIF";
+
+static void fix_framerate(int *num, int *den) {
+  // Some versions of vpxenc used 1/(2*fps) for the timebase, so
+  // we can guess the framerate using only the timebase in this
+  // case. Other files would require reading ahead to guess the
+  // timebase, like we do for webm.
+  if (*den > 0 && *den < 1000000000 && *num > 0 && *num < 1000) {
+    // Correct for the factor of 2 applied to the timebase in the encoder.
+    if (*num & 1)
+      *den *= 2;
+    else
+      *num /= 2;
+  } else {
+    // Don't know FPS for sure, and don't have readahead code
+    // (yet?), so just default to 30fps.
+    *num = 30;
+    *den = 1;
+  }
+}
+
+int file_is_ivf(struct VpxInputContext *input_ctx) {
+  char raw_hdr[32];
+  int is_ivf = 0;
+
+  if (fread(raw_hdr, 1, 32, input_ctx->file) == 32) {
+    if (memcmp(IVF_SIGNATURE, raw_hdr, 4) == 0) {
+      is_ivf = 1;
+
+      if (mem_get_le16(raw_hdr + 4) != 0) {
+        fprintf(stderr,
+                "Error: Unrecognized IVF version! This file may not"
+                " decode properly.");
+      }
+
+      input_ctx->fourcc = mem_get_le32(raw_hdr + 8);
+      input_ctx->width = mem_get_le16(raw_hdr + 12);
+      input_ctx->height = mem_get_le16(raw_hdr + 14);
+      input_ctx->framerate.numerator = mem_get_le32(raw_hdr + 16);
+      input_ctx->framerate.denominator = mem_get_le32(raw_hdr + 20);
+      fix_framerate(&input_ctx->framerate.numerator,
+                    &input_ctx->framerate.denominator);
+    }
+  }
+
+  if (!is_ivf) {
+    rewind(input_ctx->file);
+    input_ctx->detect.buf_read = 0;
+  } else {
+    input_ctx->detect.position = 4;
+  }
+  return is_ivf;
+}
+
+int ivf_read_frame(FILE *infile, uint8_t **buffer, size_t *bytes_read,
+                   size_t *buffer_size) {
+  char raw_header[IVF_FRAME_HDR_SZ] = { 0 };
+  size_t frame_size = 0;
+
+  if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) {
+    if (!feof(infile)) warn("Failed to read frame size");
+  } else {
+    frame_size = mem_get_le32(raw_header);
+
+    if (frame_size > 256 * 1024 * 1024) {
+      warn("Read invalid frame size (%u)", (unsigned int)frame_size);
+      frame_size = 0;
+    }
+
+    if (frame_size > *buffer_size) {
+      uint8_t *new_buffer = realloc(*buffer, 2 * frame_size);
+
+      if (new_buffer) {
+        *buffer = new_buffer;
+        *buffer_size = 2 * frame_size;
+      } else {
+        warn("Failed to allocate compressed data buffer");
+        frame_size = 0;
+      }
+    }
+  }
+
+  if (!feof(infile)) {
+    if (fread(*buffer, 1, frame_size, infile) != frame_size) {
+      warn("Failed to read full frame");
+      return 1;
+    }
+
+    *bytes_read = frame_size;
+    return 0;
+  }
+
+  return 1;
+}