[FFmpeg-devel] [PATCH 1/2] libavutil/libavfilter: opencl wrapper based on comments on 20130331

Stefano Sabatini stefasab at gmail.com
Sun Mar 31 19:50:23 CEST 2013


On date Sunday 2013-03-31 15:57:21 +0800, Wei Gao encoded:
> 
> From 545055bbb065fa9421848e6d7368294943793ec1 Mon Sep 17 00:00:00 2001
> From: highgod0401 <highgod0401 at gmail.com>
> Date: Sun, 31 Mar 2013 15:48:02 +0800
> Subject: [PATCH 1/2] opencl wrapper based on comments on 20130331
> 
> ---
>  configure          |   4 +
>  libavutil/Makefile |   3 +
>  libavutil/opencl.c | 746 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  libavutil/opencl.h | 185 +++++++++++++
>  4 files changed, 938 insertions(+)
>  create mode 100644 libavutil/opencl.c
>  create mode 100644 libavutil/opencl.h
> 
> diff --git a/configure b/configure
> index 8443db4..9c42a85 100755
> --- a/configure
> +++ b/configure
> @@ -233,6 +233,7 @@ External library support:
>    --enable-libxvid         enable Xvid encoding via xvidcore,
>                             native MPEG-4/Xvid encoder exists [no]
>    --enable-openal          enable OpenAL 1.1 capture support [no]
> +  --enable-opencl          enable OpenCL code
>    --enable-openssl         enable openssl [no]
>    --enable-x11grab         enable X11 grabbing [no]
>    --enable-zlib            enable zlib [autodetect]
> @@ -1178,6 +1179,7 @@ EXTERNAL_LIBRARY_LIST="
>      libxavs
>      libxvid
>      openal
> +    opencl
>      openssl
>      x11grab
>      zlib
> @@ -3982,6 +3984,7 @@ enabled openal     && { { for al_libs in "${OPENAL_LIBS}" "-lopenal" "-lOpenAL32
>                          die "ERROR: openal not found"; } &&
>                        { check_cpp_condition "AL/al.h" "defined(AL_VERSION_1_1)" ||
>                          die "ERROR: openal must be installed and version must be 1.1 or compatible"; }
> +enabled opencl     && require2 opencl CL/cl.h clEnqueueNDRangeKernel -lOpenCL
>  enabled openssl    && { check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto ||
>                          check_lib openssl/ssl.h SSL_library_init -lssl32 -leay32 ||
>                          check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto -lws2_32 -lgdi32 ||
> @@ -4350,6 +4353,7 @@ echo "network support           ${network-no}"
>  echo "threading support         ${thread_type-no}"
>  echo "safe bitstream reader     ${safe_bitstream_reader-no}"
>  echo "SDL support               ${sdl-no}"
> +echo "opencl enabled            ${opencl-no}"
>  echo "texi2html enabled         ${texi2html-no}"
>  echo "perl enabled              ${perl-no}"
>  echo "pod2man enabled           ${pod2man-no}"
> diff --git a/libavutil/Makefile b/libavutil/Makefile
> index 103ce5e..b520473 100644
> --- a/libavutil/Makefile
> +++ b/libavutil/Makefile
> @@ -52,6 +52,8 @@ HEADERS = adler32.h                                                     \
>  
>  HEADERS-$(CONFIG_LZO)                   += lzo.h
>  
> +HEADERS-$(CONFIG_OPENCL)                += opencl.h
> +
>  ARCH_HEADERS = bswap.h                                                  \
>                 intmath.h                                                \
>                 intreadwrite.h                                           \
> @@ -106,6 +108,7 @@ OBJS = adler32.o                                                        \
>         xtea.o                                                           \
>  
>  OBJS-$(CONFIG_LZO)                      += lzo.o
> +OBJS-$(CONFIG_OPENCL)                   += opencl.o
>  
>  OBJS += $(COMPAT_OBJS:%=../compat/%)
>  
> diff --git a/libavutil/opencl.c b/libavutil/opencl.c
> new file mode 100644
> index 0000000..f415fbf
> --- /dev/null
> +++ b/libavutil/opencl.c
> @@ -0,0 +1,746 @@
> +/*
> + * Copyright (C) 2012 Peng Gao <peng at multicorewareinc.com>
> + * Copyright (C) 2012 Li   Cao <li at multicorewareinc.com>
> + * Copyright (C) 2012 Wei  Gao <weigao at multicorewareinc.com>
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include "opencl.h"
> +#include "avstring.h"
> +#include "log.h"
> +#include "avassert.h"
> +
> +#if HAVE_PTHREADS
> +
> +#include <pthread.h>
> +static pthread_mutex_t atomic_opencl_lock = PTHREAD_MUTEX_INITIALIZER;
> +
> +#define LOCK_OPENCL pthread_mutex_lock(&atomic_opencl_lock);
> +#define UNLOCK_OPENCL pthread_mutex_unlock(&atomic_opencl_lock);
> +
> +#elif !HAVE_THREADS
> +#define LOCK_OPENCL
> +#define UNLOCK_OPENCL
> +#endif
> +
> +
> +#define MAX_KERNEL_NUM 500
> +#define MAX_KERNEL_CODE_NUM 200
> +
> +typedef struct KernelNode {
> +    char kernel_name[AV_OPENCL_MAX_KERNEL_NAME_LEN];

LEN+1 or SIZE

What I mean:

a name is a string, but is also a buffer. To declare a buffer
containing a string you can do either:
char kernel_name[MAX_KERNEL_NAME_LEN+1];
or
char kernel_name[MAX_KERNEL_NAME_SIZE];

mixing the two like in:
char kernel_name[AV_OPENCL_MAX_KERNEL_NAME_LEN];

is confusing, since now you're using a name with "LEN" to indicate a
buffer size.

> +    cl_kernel kernel;
> +    int kernel_ref;
> +} KernelNode;
> +
> +typedef struct UserSpecDevInfo {
> +    int dev_idx;
> +    int platform_idx;

as already noted, "device_id" and "platform_id" should be better names
assuming these fields are the same are related to the corresponding
ones in GPUEnv.

> +} UserSpecDevInfo;
> +

> +typedef struct KernelCode {
> +    int is_compiled;
> +    const char *kernel_string;
> +} KernelCode;

Note, you could declare the struct like:
typedef struct {
...
} KernelCode;

and avoid some redundancy.

> +
> +typedef struct GPUEnv {
> +    int opencl_is_inited;
> +    UserSpecDevInfo usr_spec_dev_info;

> +    cl_platform_id platform;

nit: platform_id for consistency

> +    cl_device_type device_type;
> +    cl_context context;
> +    cl_device_id *device_ids;
> +    cl_device_id device_id;
> +    cl_command_queue command_queue;
> +    int program_count;
> +    cl_program programs[MAX_KERNEL_CODE_NUM];
> +    int kernel_code_count;
> +    KernelCode kernel_code[MAX_KERNEL_CODE_NUM];
> +    int kernel_count;
> +    KernelNode kernel_node[MAX_KERNEL_NUM];

> +    int is_user_created; // 1: the opencl env is created by user and use AVOpenCLExternalInfo to pass to ffmpeg ,0:created by opencl wrapper.

/**
 * if set to 1, the OpenCL environment was created by the user and
 * passed as AVOpenCLExternalEnv when initing ,0:created by opencl wrapper.
 */
int is_user_created;

> +} GPUEnv;
> +
> +typedef struct OpenclUtils {
> +    const AVClass *class;
> +    int log_offset;
> +    void *log_ctx;
> +} OpenclUtils;
> +
> +static const AVClass openclutils_class = {"OPENCLUTILS", av_default_item_name,
> +                                                   NULL, LIBAVUTIL_VERSION_INT,
> +                                                   offsetof(OpenclUtils, log_offset),
> +                                                   offsetof(OpenclUtils, log_ctx)};
> +static OpenclUtils openclutils = {&openclutils_class};
> +static GPUEnv gpu_env;
> +
> +typedef struct OpenclErrorMsg {
> +    int err_code;
> +    const char *err_str;
> +} OpenclErrorMsg;
> +
> +static const OpenclErrorMsg opencl_err_msg[] = {
> +        {CL_DEVICE_NOT_FOUND,                               "DEVICE NOT FOUND"},
> +        {CL_DEVICE_NOT_AVAILABLE,                           "DEVICE NOT AVAILABLE"},
> +        {CL_COMPILER_NOT_AVAILABLE,                         "COMPILER NOT AVAILABLE"},
> +        {CL_MEM_OBJECT_ALLOCATION_FAILURE,                  "MEM OBJECT ALLOCATION FAILURE"},
> +        {CL_OUT_OF_RESOURCES,                               "OUT OF RESOURCES"},
> +        {CL_OUT_OF_HOST_MEMORY,                             "OUT OF HOST MEMORY"},
> +        {CL_PROFILING_INFO_NOT_AVAILABLE,                   "PROFILING INFO NOT AVAILABLE"},
> +        {CL_MEM_COPY_OVERLAP,                               "MEM COPY OVERLAP"},
> +        {CL_IMAGE_FORMAT_MISMATCH,                          "IMAGE FORMAT MISMATCH"},
> +        {CL_IMAGE_FORMAT_NOT_SUPPORTED,                     "IMAGE FORMAT NOT_SUPPORTED"},
> +        {CL_BUILD_PROGRAM_FAILURE,                          "BUILD PROGRAM FAILURE"},
> +        {CL_MAP_FAILURE,                                    "MAP FAILURE"},
> +        {CL_MISALIGNED_SUB_BUFFER_OFFSET,                   "MISALIGNED SUB BUFFER OFFSET"},
> +        {CL_EXEC_STATUS_ERROR_FOR_EVENTS_IN_WAIT_LIST,      "EXEC STATUS ERROR FOR EVENTS IN WAIT LIST"},
> +        {CL_COMPILE_PROGRAM_FAILURE,                        "COMPILE PROGRAM FAILURE"},
> +        {CL_LINKER_NOT_AVAILABLE,                           "LINKER NOT AVAILABLE"},
> +        {CL_LINK_PROGRAM_FAILURE,                           "LINK PROGRAM FAILURE"},
> +        {CL_DEVICE_PARTITION_FAILED,                        "DEVICE PARTITION FAILED"},
> +        {CL_KERNEL_ARG_INFO_NOT_AVAILABLE,                  "KERNEL ARG INFO NOT AVAILABLE"},
> +        {CL_INVALID_VALUE,                                  "INVALID VALUE"},
> +        {CL_INVALID_DEVICE_TYPE,                            "INVALID DEVICE TYPE"},
> +        {CL_INVALID_PLATFORM,                               "INVALID PLATFORM"},
> +        {CL_INVALID_DEVICE,                                 "INVALID DEVICE"},
> +        {CL_INVALID_CONTEXT,                                "INVALID CONTEXT"},
> +        {CL_INVALID_QUEUE_PROPERTIES,                       "INVALID QUEUE PROPERTIES"},
> +        {CL_INVALID_COMMAND_QUEUE,                          "INVALID COMMAND QUEUE"},
> +        {CL_INVALID_HOST_PTR,                               "INVALID HOST PTR"},
> +        {CL_INVALID_MEM_OBJECT,                             "INVALID MEM OBJECT"},
> +        {CL_INVALID_IMAGE_FORMAT_DESCRIPTOR,                "INVALID IMAGE FORMAT DESCRIPTOR"},
> +        {CL_INVALID_IMAGE_SIZE,                             "INVALID IMAGE SIZE"},
> +        {CL_INVALID_SAMPLER,                                "INVALID SAMPLER"},
> +        {CL_INVALID_BINARY,                                 "INVALID BINARY"},
> +        {CL_INVALID_BUILD_OPTIONS,                          "INVALID BUILD OPTIONS"},
> +        {CL_INVALID_PROGRAM,                                "INVALID PROGRAM"},
> +        {CL_INVALID_PROGRAM_EXECUTABLE,                     "INVALID PROGRAM EXECUTABLE"},
> +        {CL_INVALID_KERNEL_NAME,                            "INVALID KERNEL NAME"},
> +        {CL_INVALID_KERNEL_DEFINITION,                      "INVALID KERNEL DEFINITION"},
> +        {CL_INVALID_KERNEL,                                 "INVALID KERNEL"},
> +        {CL_INVALID_ARG_INDEX,                              "INVALID ARG INDEX"},
> +        {CL_INVALID_ARG_VALUE,                              "INVALID ARG VALUE"},
> +        {CL_INVALID_ARG_SIZE,                               "INVALID ARG_SIZE"},
> +        {CL_INVALID_KERNEL_ARGS,                            "INVALID KERNEL ARGS"},
> +        {CL_INVALID_WORK_DIMENSION,                         "INVALID WORK DIMENSION"},
> +        {CL_INVALID_WORK_GROUP_SIZE,                        "INVALID WORK GROUP SIZE"},
> +        {CL_INVALID_WORK_ITEM_SIZE,                         "INVALID WORK ITEM SIZE"},
> +        {CL_INVALID_GLOBAL_OFFSET,                          "INVALID GLOBAL OFFSET"},
> +        {CL_INVALID_EVENT_WAIT_LIST,                        "INVALID EVENT WAIT LIST"},
> +        {CL_INVALID_EVENT,                                  "INVALID EVENT"},
> +        {CL_INVALID_OPERATION,                              "INVALID OPERATION"},
> +        {CL_INVALID_GL_OBJECT,                              "INVALID GL OBJECT"},
> +        {CL_INVALID_BUFFER_SIZE,                            "INVALID BUFFER SIZE"},
> +        {CL_INVALID_MIP_LEVEL,                              "INVALID MIP LEVEL"},
> +        {CL_INVALID_GLOBAL_WORK_SIZE,                       "INVALID GLOBAL WORK SIZE"},
> +        {CL_INVALID_PROPERTY,                               "INVALID PROPERTY"},
> +        {CL_INVALID_IMAGE_DESCRIPTOR,                       "INVALID IMAGE DESCRIPTOR"},
> +        {CL_INVALID_COMPILER_OPTIONS,                       "INVALID COMPILER OPTIONS"},
> +        {CL_INVALID_LINKER_OPTIONS,                         "INVALID LINKER OPTIONS"},
> +        {CL_INVALID_DEVICE_PARTITION_COUNT,                 "INVALID DEVICE PARTITION COUNT"},
> +};
> +
> +static const char *opencl_errstr(cl_int status)
> +{
> +    int i;
> +    for (i = 0; i < sizeof(opencl_err_msg); i++) {
> +        if (opencl_err_msg[i].err_code == status)
> +            return opencl_err_msg[i].err_str;
> +    }
> +    return "unknown error";
> +}
> +
> +AVOpenCLExternalEnv *av_opencl_alloc_external_environment(void)
> +{
> +    AVOpenCLExternalEnv *ext = av_mallocz(sizeof(AVOpenCLExternalEnv));
> +    if (!ext) {
> +        av_log(&openclutils, AV_LOG_ERROR,
> +         "Could not malloc external opencl environment data space\n");
> +    }
> +    return ext;
> +}
> +
> +void av_opencl_free_external_environment(AVOpenCLExternalEnv *ext_opencl_env)
> +{
> +    av_freep(&ext_opencl_env);
> +}
> +
> +int av_opencl_register_kernel_code(const char *kernel_code)
> +{
> +    int i, ret = 0;
> +    LOCK_OPENCL;
> +    if (gpu_env.kernel_code_count >= MAX_KERNEL_CODE_NUM) {
> +        av_log(&openclutils, AV_LOG_ERROR,
> +         "Could not register kernel code, maximum number of registered kernel code %d already reached\n",
> +         MAX_KERNEL_CODE_NUM);
> +        ret = AVERROR(EINVAL);
> +        goto end;
> +    }
> +    for (i = 0; i < gpu_env.kernel_code_count; i++) {
> +        if (gpu_env.kernel_code[i].kernel_string == kernel_code) {
> +            av_log(&openclutils, AV_LOG_WARNING, "Same kernel code has been registered\n");
> +            goto end;
> +        }
> +    }
> +    gpu_env.kernel_code[gpu_env.kernel_code_count].kernel_string = kernel_code;
> +    gpu_env.kernel_code[gpu_env.kernel_code_count].is_compiled = 0;
> +    gpu_env.kernel_code_count++;
> +end:
> +    UNLOCK_OPENCL;
> +    return ret;
> +}
> +

> +int av_opencl_create_kernel(AVOpenCLKernelEnv *env, const char *kernel_name)
> +{
> +    cl_int status;
> +    int i, ret = 0;
> +    LOCK_OPENCL;
> +    if (strlen(kernel_name) + 1 > AV_OPENCL_MAX_KERNEL_NAME_LEN) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Created kernel name %s is too long\n", kernel_name);
> +        ret = AVERROR(EINVAL);
> +        goto end;
> +    }
> +    if (!env->kernel) {
> +        for (i = 0;i < gpu_env.kernel_count;i++) {
> +            if (av_strcasecmp(kernel_name, gpu_env.kernel_node[i].kernel_name) == 0) {
> +                env->kernel = gpu_env.kernel_node[i].kernel;
> +                gpu_env.kernel_node[i].kernel_ref++;
> +                break;
> +            }
> +        }
> +        if (!env->kernel) {
> +            if (gpu_env.kernel_count >= MAX_KERNEL_NUM) {
> +                av_log(&openclutils, AV_LOG_ERROR,
> +                "Could not create kernel with name '%s', maximum number of kernels %d already reached\n",
> +                    kernel_name, MAX_KERNEL_NUM);
> +                ret = AVERROR(EINVAL);
> +                goto end;
> +            }
> +            for (i = 0; i < gpu_env.program_count; i++) {
> +                env->kernel = clCreateKernel(gpu_env.programs[i], kernel_name, &status);
> +                if (status == CL_SUCCESS)
> +                    break;
> +            }
> +            if (status != CL_SUCCESS) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not create OpenCL kernel: %s\n", opencl_errstr(status));
> +                ret = AVERROR_EXTERNAL;
> +                goto end;
> +            }
> +            av_strlcpy(gpu_env.kernel_node[gpu_env.kernel_count].kernel_name, kernel_name,
> +                       sizeof(gpu_env.kernel_node[gpu_env.kernel_count].kernel_name));
> +            gpu_env.kernel_node[gpu_env.kernel_count].kernel= env->kernel;
> +            gpu_env.kernel_node[gpu_env.kernel_count].kernel_ref++;
> +            gpu_env.kernel_count++;
> +        }
> +        env->command_queue = gpu_env.command_queue;
> +        av_strlcpy(env->kernel_name, kernel_name, sizeof(env->kernel_name));
> +    }
> +end:
> +    UNLOCK_OPENCL;
> +    return ret;
> +}
> +
> +void av_opencl_release_kernel(AVOpenCLKernelEnv *env)
> +{
> +    cl_int status;
> +    int i;
> +    LOCK_OPENCL
> +    if (!env->kernel)
> +        goto end;
> +    for (i = 0;i < gpu_env.kernel_count;i++) {
> +        if (gpu_env.kernel_node[i].kernel == env->kernel) {
> +            if (gpu_env.kernel_node[i].kernel_ref == 1) {
> +                status = clReleaseKernel(env->kernel);
> +                if (status != CL_SUCCESS) {
> +                    av_log(&openclutils, AV_LOG_ERROR, "Could not release kernel: %s\n",
> +                          opencl_errstr(status));
> +                }
> +                gpu_env.kernel_node[i].kernel = NULL;
> +                env->kernel = NULL;

> +                memset(gpu_env.kernel_node[i].kernel_name, 0, sizeof(gpu_env.kernel_node[i].kernel_name));

gpu_env.kernel_node[i].kernel_name[0] = 0;

should be enough.


> +                gpu_env.kernel_count--;
> +            }
> +            gpu_env.kernel_node[i].kernel_ref--;
> +        }
> +    }
> +end:
> +    UNLOCK_OPENCL
> +}
> +

> +static int init_opencl_env(GPUEnv *gpu_env, AVOpenCLExternalEnv *ext_opencl_info)

nit: ext_env or ext_opencl_env or opencl_ext_env for consistency

> +{
> +    size_t device_length;
> +    cl_int status;
> +    cl_uint num_platforms, num_devices;
> +    cl_platform_id *platform_ids = NULL;
> +    cl_context_properties cps[3];
> +    char platform_name[100];
> +    int i, ret = 0;
> +    cl_device_type device_type[] = {CL_DEVICE_TYPE_GPU, CL_DEVICE_TYPE_CPU, CL_DEVICE_TYPE_DEFAULT};
> +    if (ext_opencl_info) {
> +        if (gpu_env->is_user_created)
> +            return 0;
> +        gpu_env->platform        = ext_opencl_info->platform;
> +        gpu_env->is_user_created = 1;
> +        gpu_env->command_queue   = ext_opencl_info->command_queue;
> +        gpu_env->context         = ext_opencl_info->context;
> +        gpu_env->device_ids      = ext_opencl_info->device_ids;
> +        gpu_env->device_id       = ext_opencl_info->device_id;
> +        gpu_env->device_type     = ext_opencl_info->device_type;
> +    } else {
> +        if (!gpu_env->is_user_created) {
> +            status = clGetPlatformIDs(0, NULL, &num_platforms);
> +            if (status != CL_SUCCESS) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL platform ids: %s\n", opencl_errstr(status));
> +                return AVERROR_EXTERNAL;
> +            }
> +            if (gpu_env->usr_spec_dev_info.platform_idx >= 0) {
> +                if (num_platforms < gpu_env->usr_spec_dev_info.platform_idx + 1) {
> +                    av_log(&openclutils, AV_LOG_ERROR, "User set platform index not exist\n");
> +                    return AVERROR(EINVAL);
> +                }
> +            }
> +            if (num_platforms > 0) {
> +                platform_ids = av_mallocz(num_platforms * sizeof(cl_platform_id));
> +                if (!platform_ids) {
> +                    ret = AVERROR(ENOMEM);
> +                    goto end;
> +                }
> +                status = clGetPlatformIDs(num_platforms, platform_ids, NULL);
> +                if (status != CL_SUCCESS) {
> +                    av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL platform ids: %s\n", opencl_errstr(status));
> +                    ret = AVERROR_EXTERNAL;
> +                    goto end;
> +                }
> +                i = 0;
> +                if (gpu_env->usr_spec_dev_info.platform_idx >= 0) {
> +                    i = gpu_env->usr_spec_dev_info.platform_idx;
> +                }
> +                while (i < num_platforms) {
> +                    status = clGetPlatformInfo(platform_ids[i], CL_PLATFORM_VENDOR,
> +                                               sizeof(platform_name), platform_name,
> +                                               NULL);
> +
> +                    if (status != CL_SUCCESS) {
> +                        av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL platform info: %s\n", opencl_errstr(status));
> +                        ret = AVERROR_EXTERNAL;
> +                        goto end;
> +                    }
> +                    gpu_env->platform = platform_ids[i];
> +                    status = clGetDeviceIDs(gpu_env->platform, CL_DEVICE_TYPE_GPU,
> +                                            0, NULL, &num_devices);
> +                    if (status != CL_SUCCESS) {
> +                        av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL device number:%s\n", opencl_errstr(status));
> +                        ret = AVERROR_EXTERNAL;
> +                        goto end;
> +                    }
> +                    if (num_devices == 0) {
> +                        //find CPU device
> +                        status = clGetDeviceIDs(gpu_env->platform, CL_DEVICE_TYPE_CPU,
> +                                             0, NULL, &num_devices);
> +                    }
> +                    if (status != CL_SUCCESS) {
> +                        av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL device ids: %s\n", opencl_errstr(status));
> +                        ret = AVERROR(EINVAL);;
> +                        goto end;
> +                    }
> +                    if (num_devices)
> +                       break;
> +                    if (gpu_env->usr_spec_dev_info.platform_idx >= 0) {
> +                        av_log(&openclutils, AV_LOG_ERROR, "Device number of user set platform is 0\n");
> +                        ret = AVERROR_EXTERNAL;
> +                        goto end;
> +                    }
> +                    i++;
> +
> +                }
> +            }
> +            if (!gpu_env->platform) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL platforms\n");
> +                ret = AVERROR_EXTERNAL;
> +                goto end;
> +            }
> +            if (gpu_env->usr_spec_dev_info.dev_idx >= 0) {
> +                if (num_devices < gpu_env->usr_spec_dev_info.dev_idx + 1) {
> +                    av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL device idx in the user set platform\n");
> +                    ret = AVERROR(EINVAL);;
> +                    goto end;
> +                }
> +            }
> +

> +           /*
> +                 * Use available platform.
> +                 */

weird style:

           /*
            * Use available platform.
            */

> +            av_log(&openclutils, AV_LOG_VERBOSE, "Platform Name: %s\n", platform_name);
> +            cps[0] = CL_CONTEXT_PLATFORM;
> +            cps[1] = (cl_context_properties)gpu_env->platform;
> +            cps[2] = 0;
> +            /* Check for GPU. */
> +
> +            for (i = 0; i < sizeof(device_type); i++) {
> +                gpu_env->device_type = device_type[i];
> +                gpu_env->context     = clCreateContextFromType(cps, gpu_env->device_type,
> +                                                               NULL, NULL, &status);
> +                if (status != CL_SUCCESS) {
> +                    av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL context from device type: %s\n", opencl_errstr(status));
> +                    ret = AVERROR_EXTERNAL;
> +                    goto end;
> +                }
> +                if (gpu_env->context)
> +                    break;
> +            }
> +            if (!gpu_env->context) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL context from device type\n");
> +                ret = AVERROR_EXTERNAL;
> +                goto end;
> +            }
> +            /* Detect OpenCL devices. */
> +            /* First, get the size of device list data */
> +            status = clGetContextInfo(gpu_env->context, CL_CONTEXT_DEVICES,
> +                                      0, NULL, &device_length);
> +            if (status != CL_SUCCESS) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL device length: %s\n", opencl_errstr(status));
> +                ret = AVERROR_EXTERNAL;
> +                goto end;
> +            }
> +            if (device_length == 0) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL device length\n");
> +                ret = AVERROR_EXTERNAL;
> +                goto end;
> +            }
> +            /* Now allocate memory for device list based on the size we got earlier */
> +            gpu_env->device_ids = av_mallocz(device_length);
> +            if (!gpu_env->device_ids) {
> +                ret = AVERROR(ENOMEM);
> +                goto end;
> +            }
> +            /* Now, get the device list data */
> +            status = clGetContextInfo(gpu_env->context, CL_CONTEXT_DEVICES, device_length,
> +                                      gpu_env->device_ids, NULL);
> +            if (status != CL_SUCCESS) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not get OpenCL context info: %s\n", opencl_errstr(status));
> +                ret = AVERROR_EXTERNAL;
> +                goto end;
> +            }
> +            /* Create OpenCL command queue. */
> +            i = 0;
> +            if (gpu_env->usr_spec_dev_info.dev_idx >= 0) {
> +                i = gpu_env->usr_spec_dev_info.dev_idx;
> +            }
> +            gpu_env->command_queue = clCreateCommandQueue(gpu_env->context, gpu_env->device_ids[i],
> +                                                          0, &status);
> +            if (status != CL_SUCCESS) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not create OpenCL command queue: %s\n", opencl_errstr(status));
> +                ret = AVERROR_EXTERNAL;
> +                goto end;
> +            }
> +        }
> +    }
> +end:
> +    av_free(platform_ids);
> +    return ret;
> +}
> +

> +static int compile_kernel_file(GPUEnv *gpu_env, const char *build_option)

build_options

> +{
> +    cl_int status;
> +    char *temp, *source_str = NULL;
> +    size_t source_str_len = 0;
> +    int i, ret = 0;
> +
> +    for (i = 0; i < gpu_env->kernel_code_count; i++) {
> +        if (!gpu_env->kernel_code[i].is_compiled)
> +            source_str_len += strlen(gpu_env->kernel_code[i].kernel_string);
> +    }
> +    if (!source_str_len) {
> +        return 0;
> +    }
> +    source_str = av_mallocz(source_str_len + 1);
> +    if (!source_str) {
> +        return AVERROR(ENOMEM);
> +    }
> +    temp = source_str;
> +    for (i = 0; i < gpu_env->kernel_code_count; i++) {
> +        if (!gpu_env->kernel_code[i].is_compiled) {
> +            memcpy(temp, gpu_env->kernel_code[i].kernel_string,
> +                        strlen(gpu_env->kernel_code[i].kernel_string));
> +            gpu_env->kernel_code[i].is_compiled = 1;
> +            temp += strlen(gpu_env->kernel_code[i].kernel_string);
> +        }
> +    }
> +    /* create a CL program using the kernel source */
> +    gpu_env->programs[gpu_env->program_count] = clCreateProgramWithSource(gpu_env->context,
> +                                                           1, (const char **)(&source_str),
> +                                                                   &source_str_len, &status);
> +    if(status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not create OpenCL program with source code: %s\n",
> +               opencl_errstr(status));
> +        ret = AVERROR_EXTERNAL;
> +        goto end;
> +    }
> +    if (!gpu_env->programs[gpu_env->program_count]) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Created program is NULL\n");
> +        ret = AVERROR_EXTERNAL;
> +        goto end;
> +    }

> +    i = 0;
> +    if (gpu_env->usr_spec_dev_info.dev_idx >= 0)
> +        i = gpu_env->usr_spec_dev_info.dev_idx;
> +    /* create a cl program executable for all the devices specified */
> +    if (!gpu_env->is_user_created)
> +        status = clBuildProgram(gpu_env->programs[gpu_env->program_count], 1, &gpu_env->device_ids[i],
> +                                build_option, NULL, NULL);
> +    else
> +        status = clBuildProgram(gpu_env->programs[gpu_env->program_count], 1, &(gpu_env->device_id),
> +                                 build_option, NULL, NULL);
> +
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not compile OpenCL kernel: %s\n", opencl_errstr(status));
> +        ret = AVERROR_EXTERNAL;
> +        goto end;
> +    }
> +    gpu_env->program_count++;
> +end:
> +    av_free(source_str);
> +    return ret;
> +}
> +
> +int av_opencl_init(AVDictionary *options, AVOpenCLExternalEnv *ext_opencl_info)
> +{
> +    int ret = 0;
> +    AVDictionaryEntry *opt_build_entry;
> +    AVDictionaryEntry *opt_platform_entry;
> +    AVDictionaryEntry *opt_device_entry;
> +    LOCK_OPENCL
> +    if (!gpu_env.opencl_is_inited) {
> +        opt_platform_entry = av_dict_get(options, "platform_idx", NULL, 0);
> +        opt_device_entry   = av_dict_get(options, "device_idx", NULL, 0);
> +        /*initialize devices, context, command_queue*/
> +        gpu_env.usr_spec_dev_info.platform_idx = -1;
> +        gpu_env.usr_spec_dev_info.dev_idx = -1;

> +        if (opt_platform_entry) {
> +            gpu_env.usr_spec_dev_info.platform_idx = atoi(opt_platform_entry->value);
> +        }
> +        if (opt_device_entry) {
> +            gpu_env.usr_spec_dev_info.dev_idx = atoi(opt_device_entry->value);
> +        }

atoi() is not robust, you need something more robust like strtol() and
abort in case of invalid string.

Also you may want to mention the supported options in the docs.

> +        ret = init_opencl_env(&gpu_env, ext_opencl_info);
> +        if (ret < 0)
> +            goto end;
> +        gpu_env.opencl_is_inited = 1;
> +    }
> +    /*initialize program, kernel_name, kernel_count*/

> +    opt_build_entry = av_dict_get(options, "build_option", NULL, 0);

"build_options", as stated in the docs and as we seemed to agree.

> +    if (opt_build_entry)
> +        ret = compile_kernel_file(&gpu_env, opt_build_entry->value);
> +    else
> +        ret = compile_kernel_file(&gpu_env, NULL);
> +    if (ret < 0)
> +        goto end;
> +    av_assert1(gpu_env.kernel_code_count > 0);
> +
> +end:
> +    UNLOCK_OPENCL
> +    return ret;
> +}
> +
> +void av_opencl_uninit(void)
> +{
> +    cl_int status;
> +    int i;
> +    LOCK_OPENCL
> +    if (!gpu_env.opencl_is_inited)
> +        goto end;
> +    if (gpu_env.is_user_created)
> +        goto end;
> +    for (i = 0;i < gpu_env.kernel_count;i++) {
> +        if (gpu_env.kernel_node[i].kernel)
> +            goto end;
> +    }
> +    for (i = 0; i < gpu_env.program_count; i++) {
> +        if (gpu_env.programs[i]) {
> +            status = clReleaseProgram(gpu_env.programs[i]);
> +            if (status != CL_SUCCESS) {
> +                av_log(&openclutils, AV_LOG_ERROR, "Could not release OpenCL program: %s\n", opencl_errstr(status));
> +            }
> +            gpu_env.programs[i] = NULL;
> +        }
> +    }
> +    if (gpu_env.command_queue) {
> +        status = clReleaseCommandQueue(gpu_env.command_queue);
> +        if (status != CL_SUCCESS) {
> +            av_log(&openclutils, AV_LOG_ERROR, "Could not release OpenCL command queue: %s\n", opencl_errstr(status));
> +        }
> +        gpu_env.command_queue = NULL;
> +    }
> +    if (gpu_env.context) {
> +        status = clReleaseContext(gpu_env.context);
> +        if (status != CL_SUCCESS) {
> +            av_log(&openclutils, AV_LOG_ERROR, "Could not release OpenCL context: %s\n", opencl_errstr(status));
> +        }
> +        gpu_env.context = NULL;
> +    }
> +    av_freep(&(gpu_env.device_ids));
> +    gpu_env.opencl_is_inited = 0;
> +end:
> +    UNLOCK_OPENCL
> +}
> +
> +int av_opencl_buffer_create(cl_mem *cl_buf, size_t cl_buf_size, int flags, void *host_ptr)
> +{
> +    cl_int status;
> +    *cl_buf = clCreateBuffer(gpu_env.context, flags, cl_buf_size, host_ptr, &status);
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not create OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    return 0;
> +}
> +
> +void av_opencl_buffer_release(cl_mem *cl_buf)
> +{
> +    cl_int status = 0;

> +    if (!(*cl_buf))
> +        return;

if (!cl_buf)
   return;

or it will crash if cl_buf = NULL.

> +    status = clReleaseMemObject(*cl_buf);
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not release OpenCL buffer: %s\n", opencl_errstr(status));
> +    }

> +    *cl_buf = NULL;

I don't think this makes sense.

Maybe you want to set the *pointed to* structure to 0 instead, with:
memset(cl_buf, 0, sizeof(*cl_buf));
or maybe:
*cl_buf = {0};

> +}
> +
> +int av_opencl_buffer_write(cl_mem dst_cl_buf, uint8_t *src_buf, size_t buf_size)
> +{
> +    cl_int status;
> +    void *mapped = clEnqueueMapBuffer(gpu_env.command_queue, dst_cl_buf,
> +                                      CL_TRUE,CL_MAP_WRITE, 0, sizeof(uint8_t) * buf_size,
> +                                      0, NULL, NULL, &status);
> +
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not map OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    memcpy(mapped, src_buf, buf_size);
> +
> +    status = clEnqueueUnmapMemObject(gpu_env.command_queue, dst_cl_buf, mapped, 0, NULL, NULL);
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not unmap OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    return 0;
> +}
> +
> +int av_opencl_buffer_read(uint8_t *dst_buf, cl_mem src_cl_buf, size_t buf_size)
> +{
> +    cl_int status;
> +    void *mapped = clEnqueueMapBuffer(gpu_env.command_queue, src_cl_buf,
> +                                      CL_TRUE,CL_MAP_READ, 0, buf_size,
> +                                      0, NULL, NULL, &status);
> +
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not map OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    memcpy(dst_buf, mapped, buf_size);
> +
> +    status = clEnqueueUnmapMemObject(gpu_env.command_queue, src_cl_buf, mapped, 0, NULL, NULL);
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not unmap OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    return 0;
> +}
> +
> +int av_opencl_buffer_write_image(cl_mem dst_cl_buf, size_t cl_buffer_size, int dst_cl_offset,
> +                                                    uint8_t **src_data, int *plane_size, int plane_num)
> +{
> +    int i, buffer_size = 0;
> +    uint8_t *temp;
> +    cl_int status;
> +    void *mapped;
> +    if ((unsigned int)plane_num > 8) {
> +        return AVERROR(EINVAL);
> +    }
> +    for (i = 0;i < plane_num;i++) {
> +        buffer_size += plane_size[i];
> +    }
> +    if (buffer_size > cl_buffer_size) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Cannot write image to OpenCL buffer: buffer too small\n");
> +        return AVERROR(EINVAL);
> +    }
> +    mapped = clEnqueueMapBuffer(gpu_env.command_queue, dst_cl_buf,
> +                                      CL_TRUE,CL_MAP_WRITE, 0, buffer_size + dst_cl_offset,
> +                                      0, NULL, NULL, &status);
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not map OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    temp = mapped;
> +    temp += dst_cl_offset;
> +    for (i = 0; i < plane_num; i++) {
> +        memcpy(temp, src_data[i], plane_size[i]);
> +        temp += plane_size[i];
> +    }
> +    status = clEnqueueUnmapMemObject(gpu_env.command_queue, dst_cl_buf, mapped, 0, NULL, NULL);
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not unmap OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    return 0;
> +}
> +
> +int av_opencl_buffer_read_image(uint8_t **dst_data, int *plane_size, int plane_num,
> +                                       cl_mem src_cl_buf, size_t cl_buffer_size)
> +{
> +    int i,buffer_size = 0,ret = 0;
> +    uint8_t *temp;
> +    void *mapped;
> +    cl_int status;
> +    if ((unsigned int)plane_num > 8) {
> +        return AVERROR(EINVAL);
> +    }
> +    for (i = 0;i < plane_num;i++) {
> +        buffer_size += plane_size[i];
> +    }
> +    if (buffer_size > cl_buffer_size) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Cannot write image to CPU buffer: OpenCL buffer too small\n");
> +        return AVERROR(EINVAL);
> +    }
> +    mapped = clEnqueueMapBuffer(gpu_env.command_queue, src_cl_buf,
> +                                      CL_TRUE,CL_MAP_READ, 0, buffer_size,
> +                                      0, NULL, NULL, &status);
> +
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not map OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    temp = mapped;
> +    if (ret >= 0) {
> +        for (i = 0;i < plane_num;i++) {
> +            memcpy(dst_data[i], temp, plane_size[i]);
> +            temp += plane_size[i];
> +        }
> +    }
> +    status = clEnqueueUnmapMemObject(gpu_env.command_queue, src_cl_buf, mapped, 0, NULL, NULL);
> +    if (status != CL_SUCCESS) {
> +        av_log(&openclutils, AV_LOG_ERROR, "Could not unmap OpenCL buffer: %s\n", opencl_errstr(status));
> +        return AVERROR_EXTERNAL;
> +    }
> +    return 0;
> +}
> +
> diff --git a/libavutil/opencl.h b/libavutil/opencl.h
> new file mode 100644
> index 0000000..d43e509
> --- /dev/null
> +++ b/libavutil/opencl.h
> @@ -0,0 +1,185 @@
> +/*
> + * Copyright (C) 2012 Peng Gao <peng at multicorewareinc.com>
> + * Copyright (C) 2012 Li   Cao <li at multicorewareinc.com>
> + * Copyright (C) 2012 Wei  Gao <weigao at multicorewareinc.com>
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +

Add something like this:

/**
 * @file
 * OpenCL wrapper
 *
 * This interface is considered still experimental and its API and ABI may
 * change without prior notice.
 */

> +#include "config.h"
> +#include "dict.h"

I think you can move these includes after the include guards.

> +
> +#ifndef LIBAVUTIL_OPENCLWRAPPER_H
> +#define LIBAVUTIL_OPENCLWRAPPER_H
> +
> +#include <CL/cl.h>
> +
> +#define AV_OPENCL_KERNEL( ... )# __VA_ARGS__
> +
> +#define AV_OPENCL_MAX_KERNEL_NAME_LEN 150
> +
> +typedef struct AVOpenCLKernelEnv {
> +    cl_command_queue command_queue;
> +    cl_kernel kernel;

> +    char kernel_name[AV_OPENCL_MAX_KERNEL_NAME_LEN];

char kernel_name[AV_OPENCL_MAX_KERNEL_NAME_LEN+1];

> +} AVOpenCLKernelEnv;
> +
> +typedef struct AVOpenCLExternalEnv {
> +    cl_platform_id platform;
> +    cl_device_type device_type;
> +    cl_context context;
> +    cl_device_id *device_ids;
> +    cl_device_id  device_id;
> +    cl_command_queue command_queue;
> +    char *platform_name;
> +} AVOpenCLExternalEnv;
> +

> +/**
> + * Alloc OpenCL external environment space.
> + *
> + * @return  pointer of OpenCL external environment space
> + */
> +AVOpenCLExternalEnv *av_opencl_alloc_external_environment(void);

/**
 * Allocate OpenCL external environment.
 *
 * It must be freed with av_opencl_free_external_environment().
 *
 * @return pointer to allocated OpenCL external environment
 */
AVOpenCLExternalEnv *av_opencl_alloc_external_environment(void);

Nit: for consistency with the struct name, this could be:
av_opencl_alloc_external_env()

or you could adapt the struct name instead:
AVOpenCLExternalEnvironment

but in that case you should also rename
AVOpenCLKernelEnvironment

I'm fine with both solutions, as long as they are consistent.

> +
> +/**
> + * Free OpenCL external environment space.
> + *
> + * @param ext_opencl_env    pointer of OpenCL external environment space created by av_opencl_malloc_external_environment
> + */
> +void av_opencl_free_external_environment(AVOpenCLExternalEnv *ext_opencl_env);

/**
 * Free OpenCL external environment.
 *
 * @param ext_opencl_env pointer to OpenCL external environment created by av_opencl_malloc_external_environment()
 */
void av_opencl_free_external_environment(AVOpenCLExternalEnv *ext_opencl_env);


> +
> +/**
> + * Register kernel code.
> + *
> + *  The registered kernel code is stored in a global context, and compiled
> + *  in the runtime environment when av_opencl_init() is called.
> + *
> + * @param kernel_code    kernel code to be compiled in the OpenCL runtime environment
> + * @return  >=0 on success, a negative error code in case of failure
> + */
> +int av_opencl_register_kernel_code(const char *kernel_code);
> +

> +/**
> + * Initialize the run time OpenCL environment and compile the kernel code registered by function
> + * av_opencl_register_kernel_code

... registered with av_opencl_register_kernel_code().

> + *
> + * Currently, the only accepted option is "build_options", used to set
> + * options to compile registered kernels code. See reference "OpenCL
> + * Specification Version: 1.2 chapter 5.6.4".
> + *
> + * @param options                  dictionary of key/value options
> + * @param ext_opencl_env      external OpenCL environment, created by an
> + *                                          application program, ignored if set to NULL

> + * @return  >=0 on success, a negative error value on failure

a negative _error code_ on failure

> + */
> + int av_opencl_init(AVDictionary *options, AVOpenCLExternalEnv *ext_opencl_env);
> +

> +/**
> + * Create kernel object in the specified kernel environment.
> + *
> + * @param env                  kernel environment which is filled with the environment,
> + *                                    used to run the kernel.

@param env                  pointer to kernel environment which is filled with the environment,
                            used to run the kernel

> + * @param kernel_name      kernel function name
> + * @return >=0 on success, a negative error code on failure
> + */
> +int av_opencl_create_kernel(AVOpenCLKernelEnv *env, const char *kernel_name);
> +

> +/**
> + *  Create OpenCL buffer, the buffer is used to save the data which is used or created by OpenCL kernel.
> + *
> + * @param cl_buf         the pointer of OpenCL buffer, call av_opencl_buffer_release to release the buffer.
> + * @param cl_buf_size  size in bytes of the OpenCL buffer to create
> + * @param flags           the flags which used to control buffer attributes
> + * @param host_ptr      the host pointer of OpenCL buffer
> + * @return  >=0 on success, a negative error code in case of failure
> + */
> +int av_opencl_buffer_create(cl_mem *cl_buf, size_t cl_buf_size, int flags, void *host_ptr);

/**
 * Create OpenCL buffer.
 *
 * The buffer is used to save the data used or created by an OpenCL
 * kernel.
 * The created buffer must be released with av_opencl_buffer_release().
 *
 * See clCreateBuffer() function reference for more information about
 * the parameters.
 *
 * @param cl_buf       pointer to OpenCL buffer
 * @param cl_buf_size  size in bytes of the OpenCL buffer to create
 * @param flags        flags used to control buffer attributes
 * @param host_ptr     host pointer of the OpenCL buffer
 * @return >=0 on success, a negative error code in case of failure
 */
int av_opencl_buffer_create(cl_mem *cl_buf, size_t cl_buf_size, int flags, void *host_ptr);


> +
> +/**
> + * Write OpenCL buffer with data from src_buf.
> + *
> + * @param dst_cl_buf        pointer to OpenCL destination buffer
> + * @param src_buf           pointer to source buffer
> + * @param buf_size          size in bytes of the source and destination buffers
> + * @return >=0 on success, a negative error code in case of failure
> + */
> +int av_opencl_buffer_write(cl_mem dst_cl_buf, uint8_t *src_buf, size_t buf_size);
> +
> +/**
> + * Read data from OpenCL buffer to memory buffer.
> + *
> + * @param dst_buf           pointer to destination buffer (CPU memory)
> + * @param src_cl_buf        pointer to source OpenCL buffer
> + * @param buf_size          size in bytes of the source and destination buffers
> + * @return >=0 on success, a negative error code in case of failure
> + */
> +int av_opencl_buffer_read(uint8_t *dst_buf, cl_mem src_cl_buf, size_t buf_size);
> +
> +/**
> + * Write image data from memory to OpenCL buffer.
> + *
> + * The source must be an array of pointers to image plane buffers.
> + *
> + * @param dst_cl_buf         pointer to destination OpenCL buffer
> + * @param dst_cl_buf_size    size in bytes of OpenCL buffer
> + * @param dst_cl_buf_offset  the offset of the OpenCL buffer start position
> + * @param src_data           array of pointers to source plane buffers
> + * @param src_plane_sizes    array of sizes in bytes of the source plane buffers
> + * @param src_plane_num      number of source image planes
> + * @return >=0 on success, a negative error code in case of failure
> + */

> +int av_opencl_buffer_write_image(cl_mem dst_cl_buf, size_t cl_buffer_size, int dst_cl_offset,
> +                                                       uint8_t **src_data, int *plane_size, int plane_num);

Nit: weird indent:

int av_opencl_buffer_write_image(cl_mem dst_cl_buf, size_t cl_buffer_size, int dst_cl_offset,
                                 uint8_t **src_data, int *plane_size, int plane_num);

> +/**
> + * Read image data from OpenCL buffer.
> + *
> + * src buffer is OpenCL buffer, dst buffer is frame buffer(data[0],data[1]....).
> + *
> + * @param dst_data           array of pointers to destination plane buffers
> + * @param dst_plane_sizes    array of pointers to destination plane buffers
> + * @param dst_plane_num      number of destination image planes
> + * @param src_cl_buf         pointer to source OpenCL buffer
> + * @param src_cl_buf_size    size in bytes of OpenCL buffer
> + * @return >=0 on success, a negative error code in case of failure
> + */
> +

> +int av_opencl_buffer_read_image(uint8_t **dst_data, int *plane_size, int plane_num,
> +                                       cl_mem src_cl_buf, size_t cl_buffer_size);

Nit: weird indent

> +/**
> + * Release OpenCL buffer.
> + *

> + * @param cl_buf  pointer of OpenCL buffer to release, which was previously filled with av_opencl_buffer_create()

pointer *to* OpenCL buffer to release, ...

> + */
> +void av_opencl_buffer_release(cl_mem *cl_buf);
> +
> +/**
> + *  Release kernel object.
> + *
> + * @param env  kernel environment where the kernel object was created with av_opencl_create_kernel

nit: av_opencl_create_kernel() so doxygen will auto-create a link to
the function.

> + */
> +void av_opencl_release_kernel(AVOpenCLKernelEnv *env);
> +
> +/**
> + *  Release OpenCL environment.
> + *
> + * The OpenCL environment is effectively released only if all the created
> + * kernels had been released with av_opencl_release_kernel().
> + */
> +void av_opencl_uninit(void);
> +
> +#endif/*LIBAVUTIL_OPENCL_H*/
> +
> -- 
> 1.7.11.msysgit.1
> 
-- 
FFmpeg = Fiendish and Frenzy Magical Puritan Ecumenical Gargoyle


More information about the ffmpeg-devel mailing list