diff --git a/modules/camera/3_4/Android.mk b/modules/camera/3_4/Android.mk
index bea434a..ad02c20 100644
--- a/modules/camera/3_4/Android.mk
+++ b/modules/camera/3_4/Android.mk
@@ -35,6 +35,7 @@
     libcamera_client \
     libcamera_metadata \
     libcutils \
+    libhardware \
     liblog \
     libnativehelper \
     libsync \
@@ -51,6 +52,7 @@
   StreamFormat.cpp \
   V4L2Camera.cpp \
   V4L2CameraHAL.cpp \
+  V4L2Gralloc.cpp \
   V4L2Wrapper.cpp \
 
 LOCAL_CFLAGS += -Wall -Wextra -fvisibility=hidden
diff --git a/modules/camera/3_4/V4L2Camera.cpp b/modules/camera/3_4/V4L2Camera.cpp
index e94a561..f27dc1f 100644
--- a/modules/camera/3_4/V4L2Camera.cpp
+++ b/modules/camera/3_4/V4L2Camera.cpp
@@ -28,6 +28,7 @@
 #include <nativehelper/ScopedFd.h>
 
 #include "Common.h"
+#include "V4L2Gralloc.h"
 
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
 
@@ -53,6 +54,7 @@
       mOutStreamFormat(0),
       mOutStreamWidth(0),
       mOutStreamHeight(0),
+      mOutStreamBytesPerLine(0),
       mOutStreamMaxBuffers(0),
       mTemplatesInitialized(false),
       mCharacteristicsInitialized(false) {
@@ -112,6 +114,7 @@
   mOutStreamFormat = 0;
   mOutStreamWidth = 0;
   mOutStreamHeight = 0;
+  mOutStreamBytesPerLine = 0;
   mOutStreamMaxBuffers = 0;
 }
 
@@ -308,8 +311,9 @@
     return res;
   }
 
-  // V4L2 doesn't support querying this, so we generously assume up to 3 MB.
-  int32_t max_jpeg_size = 3000000;
+  // V4L2 doesn't support querying this,
+  // so instead use a constant (defined in V4L2Gralloc.h).
+  int32_t max_jpeg_size = V4L2_MAX_JPEG_SIZE;
   res = info.update(ANDROID_JPEG_MAX_SIZE,
                     &max_jpeg_size, 1);
   if (res != android::OK) {
@@ -718,6 +722,21 @@
   HAL_LOG_ENTER();
   int res;
 
+  // Initialize and check the gralloc module.
+  const hw_module_t* module;
+  res = hw_get_module(GRALLOC_HARDWARE_MODULE_ID, &module);
+  if (res) {
+    HAL_LOGE("Couldn't get gralloc module.");
+    return -ENODEV;
+  }
+  const gralloc_module_t* gralloc =
+      reinterpret_cast<const gralloc_module_t*>(module);
+  mGralloc = V4L2Gralloc(gralloc);
+  if (!mGralloc.isValid()) {
+    HAL_LOGE("Invalid gralloc module.");
+    return -ENODEV;
+  }
+
   // Templates should be set up if they haven't already been.
   if (!mTemplatesInitialized) {
     res = initTemplates();
@@ -1358,6 +1377,7 @@
   mOutStreamFormat = format.fmt.pix.pixelformat;
   mOutStreamWidth = format.fmt.pix.width;
   mOutStreamHeight = format.fmt.pix.height;
+  mOutStreamBytesPerLine = format.fmt.pix.bytesperline;
   // Since our format changed, our maxBuffers may be incorrect.
   mOutStreamMaxBuffers = 0;
 
diff --git a/modules/camera/3_4/V4L2Camera.h b/modules/camera/3_4/V4L2Camera.h
index c9a7a71..bb6aac8 100644
--- a/modules/camera/3_4/V4L2Camera.h
+++ b/modules/camera/3_4/V4L2Camera.h
@@ -29,6 +29,7 @@
 #include "ArrayVector.h"
 #include "Camera.h"
 #include "Common.h"
+#include "V4L2Gralloc.h"
 
 namespace v4l2_camera_hal {
 // V4L2Camera is a specific V4L2-supported camera device. The Camera object
@@ -75,6 +76,8 @@
   const std::string mDevicePath;
   // The opened device fd.
   ScopedFd mDeviceFd;
+  // Gralloc helper.
+  V4L2Gralloc mGralloc;
   // Lock protecting use of the device.
   android::Mutex mDeviceLock;
   // Wrapper around ioctl.
@@ -86,6 +89,7 @@
   uint32_t mOutStreamFormat;
   uint32_t mOutStreamWidth;
   uint32_t mOutStreamHeight;
+  uint32_t mOutStreamBytesPerLine;
   uint32_t mOutStreamMaxBuffers;
 
   bool mTemplatesInitialized;
diff --git a/modules/camera/3_4/V4L2Gralloc.cpp b/modules/camera/3_4/V4L2Gralloc.cpp
new file mode 100644
index 0000000..8ffd262
--- /dev/null
+++ b/modules/camera/3_4/V4L2Gralloc.cpp
@@ -0,0 +1,261 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "V4L2Gralloc.h"
+
+#include <linux/videodev2.h>
+
+#include <cstdlib>
+
+#include <hardware/camera3.h>
+#include <hardware/gralloc.h>
+#include <system/graphics.h>
+
+#include "Common.h"
+
+namespace v4l2_camera_hal {
+
+// Copy |height| lines from |src| to |dest|,
+// where |src| and |dest| may have different line lengths.
+void copyWithPadding(uint8_t* dest, const uint8_t* src, size_t dest_stride,
+                     size_t src_stride, size_t height) {
+  size_t copy_stride = dest_stride;
+  if (copy_stride > src_stride) {
+    // Adding padding, not reducing. 0 out the extra memory.
+    memset(dest, 0, src_stride * height);
+    copy_stride = src_stride;
+  }
+  uint8_t* dest_line_start = dest;
+  const uint8_t* src_line_start = src;
+  for (size_t row = 0; row < height; ++row,
+           dest_line_start += dest_stride, src_line_start += src_stride) {
+    memcpy(dest_line_start, src_line_start, copy_stride);
+  }
+}
+
+V4L2Gralloc::V4L2Gralloc(const gralloc_module_t* module)
+    : mModule(module) {
+  HAL_LOG_ENTER();
+}
+
+V4L2Gralloc::~V4L2Gralloc() {
+  HAL_LOG_ENTER();
+
+  // Unlock buffers that are still locked.
+  for (auto const& entry : mBufferMap) {
+    mModule->unlock(mModule, *entry.second->camera_buffer->buffer);
+    // Clean up dynamically allocated stuff.
+    if (entry.second->transform_dest) {
+      delete [] reinterpret_cast<uint8_t*>(entry.first);
+    }
+    delete entry.second;
+  }
+}
+
+bool V4L2Gralloc::isValid() {
+  HAL_LOG_ENTER();
+
+  // This helper only supports Gralloc v0, not Gralloc V1.
+  if (mModule->common.module_api_version > GRALLOC_MODULE_API_VERSION_0_3) {
+    HAL_LOGE("Invalid gralloc version %x. Only 0.3 (%x) "
+             "and below are supported by this HAL.",
+             mModule->common.module_api_version,
+             GRALLOC_MODULE_API_VERSION_0_3);
+    return false;
+  }
+
+  return true;
+}
+
+int V4L2Gralloc::lock(const camera3_stream_buffer_t* camera_buffer,
+                      uint32_t bytes_per_line,
+                      /*out*/ v4l2_buffer* device_buffer) {
+  HAL_LOG_ENTER();
+
+  // Lock the camera buffer (varies depending on if the buffer is YUV or not).
+  std::unique_ptr<BufferData> buffer_data(new BufferData {
+      camera_buffer, nullptr, bytes_per_line});
+  buffer_handle_t buffer = *camera_buffer->buffer;
+  void* data;
+  size_t size;
+  camera3_stream_t* stream = camera_buffer->stream;
+  switch(stream->format) {
+    // TODO(b/30119452): support more YCbCr formats.
+    case HAL_PIXEL_FORMAT_YCbCr_420_888:
+      android_ycbcr yuv_data;
+      mModule->lock_ycbcr(mModule, buffer, stream->usage, 0, 0,
+                          stream->width, stream->height, &yuv_data);
+      // YUV_420_888 = 1.5 planes (1 Y plane, 1/4 Cb, 1/4 Cr).
+      size = bytes_per_line * stream->height * 3 / 2;
+
+      // Check if gralloc format matches v4l2 format
+      // (same padding, not interleaved, contiguous).
+      if (yuv_data.ystride == bytes_per_line &&
+          yuv_data.cstride == bytes_per_line / 2 &&
+          yuv_data.chroma_step == 1 &&
+          (reinterpret_cast<uint8_t*>(yuv_data.cb) ==
+           reinterpret_cast<uint8_t*>(yuv_data.y) +
+           (stream->height * yuv_data.ystride)) &&
+          (reinterpret_cast<uint8_t*>(yuv_data.cr) ==
+           reinterpret_cast<uint8_t*>(yuv_data.cb) +
+           (stream->height / 2 * yuv_data.cstride))) {
+        // If so, great, point to the beginning.
+        HAL_LOGV("V4L2 YUV matches gralloc YUV.");
+        data = yuv_data.y;
+      } else {
+        // If not, allocate a contiguous buffer of appropriate size
+        // (to be transformed back upon unlock).
+        HAL_LOGV("Need to transform V4L2 YUV to gralloc YUV.");
+        data = new uint8_t[size];
+        // Make a dynamically-allocated copy of yuv_data,
+        // since it will be needed at transform time.
+        buffer_data->transform_dest.reset(new android_ycbcr(yuv_data));
+      }
+      break;
+    case HAL_PIXEL_FORMAT_BLOB:
+      // Jpeg buffers are just contiguous blobs; always max_size * 1.
+      size = V4L2_MAX_JPEG_SIZE;
+      mModule->lock(mModule, buffer, stream->usage, 0, 0, size, 1, &data);
+      break;
+    default:
+      return -EINVAL;
+  }
+
+  // Set up the device buffer.
+  static_assert(sizeof(unsigned long) >= sizeof(void*),
+                "void* must be able to fit in the v4l2_buffer m.userptr "
+                "field (unsigned long) for this code to work");
+  device_buffer->m.userptr = reinterpret_cast<unsigned long>(data);
+  device_buffer->length = size;
+
+  // Note the mapping of data:buffer info for when unlock is called.
+  mBufferMap.emplace(data, buffer_data.release());
+
+  return 0;
+}
+
+int V4L2Gralloc::unlock(const v4l2_buffer* device_buffer) {
+  HAL_LOG_ENTER();
+
+  // TODO(b/30000211): support multi-planar data (video_capture_mplane).
+  if (device_buffer->type != V4L2_BUF_TYPE_VIDEO_CAPTURE) {
+    return -EINVAL;
+  }
+
+  void* data = reinterpret_cast<void*>(device_buffer->m.userptr);
+
+  // Find and pop the matching entry in the map.
+  auto map_entry = mBufferMap.find(data);
+  if (map_entry == mBufferMap.end()) {
+    HAL_LOGE("No matching buffer for data at %p", data);
+    return -EINVAL;
+  }
+  std::unique_ptr<const BufferData> buffer_data(map_entry->second);
+  mBufferMap.erase(map_entry);
+
+  const camera3_stream_buffer_t* camera_buffer = buffer_data->camera_buffer;
+  const buffer_handle_t buffer = *camera_buffer->buffer;
+
+  // Check for transform.
+  if (buffer_data->transform_dest) {
+    HAL_LOGV("Transforming V4L2 YUV to gralloc YUV.");
+    // In this case data was allocated by this class, put it in a unique_ptr
+    // to ensure it gets cleaned up no matter which way this function exits.
+    std::unique_ptr<uint8_t[]> data_cleanup(reinterpret_cast<uint8_t*>(data));
+
+    uint32_t bytes_per_line = buffer_data->v4l2_bytes_per_line;
+    android_ycbcr* yuv_data = buffer_data->transform_dest.get();
+
+    // Should only occur in error situations.
+    if (device_buffer->bytesused == 0) {
+      return -EINVAL;
+    }
+
+    // Transform V4L2 to Gralloc, copying each plane to the correct place,
+    // adjusting padding, and interleaving if necessary.
+    uint32_t height = camera_buffer->stream->height;
+    // Y data first.
+    size_t y_len = bytes_per_line * height;
+    if (yuv_data->ystride == bytes_per_line) {
+      // Data should match exactly.
+      memcpy(yuv_data->y, data, y_len);
+    } else {
+      HAL_LOGV("Changing padding on Y plane from %u to %u.",
+               bytes_per_line, yuv_data->ystride);
+      // Wrong padding from V4L2.
+      copyWithPadding(reinterpret_cast<uint8_t*>(yuv_data->y),
+                      reinterpret_cast<uint8_t*>(data),
+                      yuv_data->ystride, bytes_per_line, height);
+    }
+    // C data.
+    // TODO(b/30119452): These calculations assume YCbCr_420_888.
+    size_t c_len = y_len / 4;
+    uint32_t c_bytes_per_line = bytes_per_line / 2;
+    // V4L2 is packed, meaning the data is stored as contiguous {y, cb, cr}.
+    uint8_t* cb_device = reinterpret_cast<uint8_t*>(data) + y_len;
+    uint8_t* cr_device = cb_device + c_len;
+    size_t step = yuv_data->chroma_step;
+    if (step == 1) {
+      // Still planar.
+      if (yuv_data->cstride == c_bytes_per_line) {
+        // Data should match exactly.
+        memcpy(yuv_data->cb, cb_device, c_len);
+        memcpy(yuv_data->cr, cr_device, c_len);
+      } else {
+        HAL_LOGV("Changing padding on C plane from %u to %u.",
+                 c_bytes_per_line, yuv_data->cstride);
+        // Wrong padding from V4L2.
+        copyWithPadding(reinterpret_cast<uint8_t*>(yuv_data->cb),
+                        cb_device, yuv_data->cstride,
+                        c_bytes_per_line, height / 2);
+        copyWithPadding(reinterpret_cast<uint8_t*>(yuv_data->cr),
+                        cr_device, yuv_data->cstride,
+                        c_bytes_per_line, height / 2);
+      }
+    } else {
+      // Desire semiplanar (cb and cr interleaved).
+      HAL_LOGV("Interleaving cb and cr. Padding going from %u to %u.",
+               c_bytes_per_line, yuv_data->cstride);
+      uint32_t c_height = height / 2;
+      uint32_t c_width = camera_buffer->stream->width / 2;
+      // Zero out destination
+      uint8_t* cb_gralloc = reinterpret_cast<uint8_t*>(yuv_data->cb);
+      uint8_t* cr_gralloc = reinterpret_cast<uint8_t*>(yuv_data->cr);
+      memset(cb_gralloc, 0, c_width * c_height * step);
+
+      // Interleaving means we need to copy the cb and cr bytes one by one.
+      for (size_t line = 0; line < c_height; ++line,
+               cb_gralloc += yuv_data->cstride, cr_gralloc += yuv_data->cstride,
+               cb_device += c_bytes_per_line, cr_device += c_bytes_per_line) {
+        for (size_t i = 0; i < c_width; ++i) {
+          *(cb_gralloc + (i * step)) = *(cb_device + i);
+          *(cr_gralloc + (i * step)) = *(cr_device + i);
+        }
+      }
+    }
+  }
+
+  // Unlock.
+  int res = mModule->unlock(mModule, buffer);
+  if (res) {
+    HAL_LOGE("Failed to unlock buffer at %p", buffer);
+    return -ENODEV;
+  }
+
+  return 0;
+}
+
+} // namespace default_camera_hal
diff --git a/modules/camera/3_4/V4L2Gralloc.h b/modules/camera/3_4/V4L2Gralloc.h
new file mode 100644
index 0000000..6e37adb
--- /dev/null
+++ b/modules/camera/3_4/V4L2Gralloc.h
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef V4L2_GRALLOC_H
+#define V4L2_GRALLOC_H
+
+#include <linux/videodev2.h>
+
+#include <unordered_map>
+
+#include <hardware/camera3.h>
+#include <hardware/gralloc.h>
+#include <system/graphics.h>
+
+namespace v4l2_camera_hal {
+
+// Generously allow up to 3MB.
+static constexpr size_t V4L2_MAX_JPEG_SIZE = 3000000;
+
+// V4L2Gralloc is a wrapper around relevant parts of a gralloc module,
+// with some assistive transformations.
+class V4L2Gralloc {
+public:
+  V4L2Gralloc(const gralloc_module_t* module = nullptr);
+  ~V4L2Gralloc();
+
+  // Lock a camera buffer. Sets device buffer user pointer and length.
+  int lock(const camera3_stream_buffer_t* camera_buffer,
+           uint32_t bytes_per_line,
+           v4l2_buffer* device_buffer);
+  // Unlock a buffer that was locked by this helper (equality determined
+  // based on buffer user pointer, not the specific object).
+  int unlock(const v4l2_buffer* device_buffer);
+
+  // Check that the module passed in to the constructor is supported.
+  bool isValid();
+
+private:
+  const gralloc_module_t* mModule;
+
+  struct BufferData {
+    const camera3_stream_buffer_t* camera_buffer;
+    // Below fields only used when a ycbcr format transform is necessary.
+    std::unique_ptr<android_ycbcr> transform_dest;  // nullptr if no transform.
+    uint32_t v4l2_bytes_per_line;
+  };
+  // Map data pointer : BufferData about that buffer.
+  std::unordered_map<void*, const BufferData*> mBufferMap;
+};
+} // namespace default_camera_hal
+
+#endif // CAMERA_GRALLOC_H_