libavcodec/vda_h264.c - chromium/third_party/ffmpeg - Git at Google

 /*
  * VDA H264 HW acceleration.
  *
  * copyright (c) 2011 Sebastien Zwickert
  *
  * 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 <CoreFoundation/CFDictionary.h>
 #include <CoreFoundation/CFNumber.h>
 #include <CoreFoundation/CFData.h>

 #include "vda.h"
 #include "libavutil/avutil.h"
 #include "h264.h"

 struct vda_buffer {
     CVPixelBufferRef cv_buffer;
 };
 #include "internal.h"
 #include "vda_internal.h"

 typedef struct VDAContext {
     // The current bitstream buffer.
     uint8_t             *bitstream;

     // The current size of the bitstream.
     int                  bitstream_size;

     // The reference size used for fast reallocation.
     int                  allocated_size;

     CVImageBufferRef frame;
 } VDAContext;

 /* Decoder callback that adds the vda frame to the queue in display order. */
 static void vda_decoder_callback(void *vda_hw_ctx,
                                  CFDictionaryRef user_info,
                                  OSStatus status,
                                  uint32_t infoFlags,
                                  CVImageBufferRef image_buffer)
 {
     struct vda_context *vda_ctx = vda_hw_ctx;

     if (infoFlags & kVDADecodeInfo_FrameDropped)
         vda_ctx->cv_buffer = NULL;

     if (!image_buffer)
         return;

     if (vda_ctx->cv_pix_fmt_type != CVPixelBufferGetPixelFormatType(image_buffer))
         return;

     vda_ctx->cv_buffer = CVPixelBufferRetain(image_buffer);
 }

 static int vda_sync_decode(VDAContext *ctx, struct vda_context *vda_ctx)
 {
     OSStatus status;
     CFDataRef coded_frame;
     uint32_t flush_flags = 1 << 0; ///< kVDADecoderFlush_emitFrames

     coded_frame = CFDataCreate(kCFAllocatorDefault,
                                ctx->bitstream,
                                ctx->bitstream_size);

     status = VDADecoderDecode(vda_ctx->decoder, 0, coded_frame, NULL);

     if (kVDADecoderNoErr == status)
         status = VDADecoderFlush(vda_ctx->decoder, flush_flags);

     CFRelease(coded_frame);

     return status;
 }


 static int vda_old_h264_start_frame(AVCodecContext *avctx,
                                 av_unused const uint8_t *buffer,
                                 av_unused uint32_t size)
 {
     VDAContext *vda = avctx->internal->hwaccel_priv_data;
     struct vda_context *vda_ctx = avctx->hwaccel_context;

     if (!vda_ctx->decoder)
         return -1;

     vda->bitstream_size = 0;

     return 0;
 }

 static int vda_old_h264_decode_slice(AVCodecContext *avctx,
                                  const uint8_t *buffer,
                                  uint32_t size)
 {
     VDAContext *vda             = avctx->internal->hwaccel_priv_data;
     struct vda_context *vda_ctx = avctx->hwaccel_context;
     void *tmp;

     if (!vda_ctx->decoder)
         return -1;

     tmp = av_fast_realloc(vda->bitstream,
                           &vda->allocated_size,
                           vda->bitstream_size + size + 4);
     if (!tmp)
         return AVERROR(ENOMEM);

     vda->bitstream = tmp;

     AV_WB32(vda->bitstream + vda->bitstream_size, size);
     memcpy(vda->bitstream + vda->bitstream_size + 4, buffer, size);

     vda->bitstream_size += size + 4;

     return 0;
 }

 static void vda_h264_release_buffer(void *opaque, uint8_t *data)
 {
     struct vda_buffer *context = opaque;
     CVPixelBufferRelease(context->cv_buffer);
     av_free(context);
 }

 static int vda_old_h264_end_frame(AVCodecContext *avctx)
 {
     H264Context *h                      = avctx->priv_data;
     VDAContext *vda                     = avctx->internal->hwaccel_priv_data;
     struct vda_context *vda_ctx         = avctx->hwaccel_context;
     AVFrame *frame                      = &h->cur_pic_ptr->f;
     struct vda_buffer *context;
     AVBufferRef *buffer;
     int status;

     if (!vda_ctx->decoder || !vda->bitstream)
         return -1;

     status = vda_sync_decode(vda, vda_ctx);
     frame->data[3] = (void*)vda_ctx->cv_buffer;

     if (status)
         av_log(avctx, AV_LOG_ERROR, "Failed to decode frame (%d)\n", status);

     if (!vda_ctx->use_ref_buffer || status)
         return status;

     context = av_mallocz(sizeof(*context));
     buffer = av_buffer_create(NULL, 0, vda_h264_release_buffer, context, 0);
     if (!context || !buffer) {
         CVPixelBufferRelease(vda_ctx->cv_buffer);
         av_free(context);
         return -1;
     }

     context->cv_buffer = vda_ctx->cv_buffer;
     frame->buf[3] = buffer;

     return status;
 }

 int ff_vda_create_decoder(struct vda_context *vda_ctx,
                           uint8_t *extradata,
                           int extradata_size)
 {
     OSStatus status;
     CFNumberRef height;
     CFNumberRef width;
     CFNumberRef format;
     CFDataRef avc_data;
     CFMutableDictionaryRef config_info;
     CFMutableDictionaryRef buffer_attributes;
     CFMutableDictionaryRef io_surface_properties;
     CFNumberRef cv_pix_fmt;

     vda_ctx->priv_bitstream = NULL;
     vda_ctx->priv_allocated_size = 0;

     /* Each VCL NAL in the bitstream sent to the decoder
      * is preceded by a 4 bytes length header.
      * Change the avcC atom header if needed, to signal headers of 4 bytes. */
     if (extradata_size >= 4 && (extradata[4] & 0x03) != 0x03) {
         uint8_t *rw_extradata;

         if (!(rw_extradata = av_malloc(extradata_size)))
             return AVERROR(ENOMEM);

         memcpy(rw_extradata, extradata, extradata_size);

         rw_extradata[4] |= 0x03;

         avc_data = CFDataCreate(kCFAllocatorDefault, rw_extradata, extradata_size);

         av_freep(&rw_extradata);
     } else {
         avc_data = CFDataCreate(kCFAllocatorDefault, extradata, extradata_size);
     }

     config_info = CFDictionaryCreateMutable(kCFAllocatorDefault,
                                             4,
                                             &kCFTypeDictionaryKeyCallBacks,
                                             &kCFTypeDictionaryValueCallBacks);

     height   = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &vda_ctx->height);
     width    = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &vda_ctx->width);
     format   = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &vda_ctx->format);

     CFDictionarySetValue(config_info, kVDADecoderConfiguration_Height, height);
     CFDictionarySetValue(config_info, kVDADecoderConfiguration_Width, width);
     CFDictionarySetValue(config_info, kVDADecoderConfiguration_SourceFormat, format);
     CFDictionarySetValue(config_info, kVDADecoderConfiguration_avcCData, avc_data);

     buffer_attributes = CFDictionaryCreateMutable(kCFAllocatorDefault,
                                                   2,
                                                   &kCFTypeDictionaryKeyCallBacks,
                                                   &kCFTypeDictionaryValueCallBacks);
     io_surface_properties = CFDictionaryCreateMutable(kCFAllocatorDefault,
                                                       0,
                                                       &kCFTypeDictionaryKeyCallBacks,
                                                       &kCFTypeDictionaryValueCallBacks);
     cv_pix_fmt  = CFNumberCreate(kCFAllocatorDefault,
                                  kCFNumberSInt32Type,
                                  &vda_ctx->cv_pix_fmt_type);
     CFDictionarySetValue(buffer_attributes,
                          kCVPixelBufferPixelFormatTypeKey,
                          cv_pix_fmt);
     CFDictionarySetValue(buffer_attributes,
                          kCVPixelBufferIOSurfacePropertiesKey,
                          io_surface_properties);

     status = VDADecoderCreate(config_info,
                               buffer_attributes,
                               (VDADecoderOutputCallback *)vda_decoder_callback,
                               vda_ctx,
                               &vda_ctx->decoder);

     CFRelease(height);
     CFRelease(width);
     CFRelease(format);
     CFRelease(avc_data);
     CFRelease(config_info);
     CFRelease(io_surface_properties);
     CFRelease(cv_pix_fmt);
     CFRelease(buffer_attributes);

     return status;
 }

 int ff_vda_destroy_decoder(struct vda_context *vda_ctx)
 {
     OSStatus status = kVDADecoderNoErr;

     if (vda_ctx->decoder)
         status = VDADecoderDestroy(vda_ctx->decoder);

     return status;
 }

 static int vda_h264_uninit(AVCodecContext *avctx)
 {
     VDAContext *vda = avctx->internal->hwaccel_priv_data;
     if (vda) {
         av_freep(&vda->bitstream);
         if (vda->frame)
             CVPixelBufferRelease(vda->frame);
     }
     return 0;
 }

 AVHWAccel ff_h264_vda_old_hwaccel = {
     .name           = "h264_vda",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_H264,
     .pix_fmt        = AV_PIX_FMT_VDA_VLD,
     .start_frame    = vda_old_h264_start_frame,
     .decode_slice   = vda_old_h264_decode_slice,
     .end_frame      = vda_old_h264_end_frame,
     .uninit         = vda_h264_uninit,
     .priv_data_size = sizeof(VDAContext),
 };

 void ff_vda_output_callback(void *opaque,
                             CFDictionaryRef user_info,
                             OSStatus status,
                             uint32_t infoFlags,
                             CVImageBufferRef image_buffer)
 {
     AVCodecContext *ctx = opaque;
     VDAContext *vda = ctx->internal->hwaccel_priv_data;


     if (vda->frame) {
         CVPixelBufferRelease(vda->frame);
         vda->frame = NULL;
     }

     if (!image_buffer)
         return;

     vda->frame = CVPixelBufferRetain(image_buffer);
 }

 static int vda_h264_start_frame(AVCodecContext *avctx,
                                 const uint8_t *buffer,
                                 uint32_t size)
 {
     VDAContext *vda = avctx->internal->hwaccel_priv_data;

     vda->bitstream_size = 0;

     return 0;
 }

 static int vda_h264_decode_slice(AVCodecContext *avctx,
                                  const uint8_t *buffer,
                                  uint32_t size)
 {
     VDAContext *vda       = avctx->internal->hwaccel_priv_data;
     void *tmp;

     tmp = av_fast_realloc(vda->bitstream,
                           &vda->allocated_size,
                           vda->bitstream_size + size + 4);
     if (!tmp)
         return AVERROR(ENOMEM);

     vda->bitstream = tmp;

     AV_WB32(vda->bitstream + vda->bitstream_size, size);
     memcpy(vda->bitstream + vda->bitstream_size + 4, buffer, size);

     vda->bitstream_size += size + 4;

     return 0;
 }

 static void release_buffer(void *opaque, uint8_t *data)
 {
     CVImageBufferRef frame = (CVImageBufferRef)data;
     CVPixelBufferRelease(frame);
 }

 static int vda_h264_end_frame(AVCodecContext *avctx)
 {
     H264Context *h        = avctx->priv_data;
     VDAContext *vda       = avctx->internal->hwaccel_priv_data;
     AVVDAContext *vda_ctx = avctx->hwaccel_context;
     AVFrame *frame        = &h->cur_pic_ptr->f;
     uint32_t flush_flags  = 1 << 0; ///< kVDADecoderFlush_emitFrames
     CFDataRef coded_frame;
     OSStatus status;

     if (!vda->bitstream_size)
         return AVERROR_INVALIDDATA;


     coded_frame = CFDataCreate(kCFAllocatorDefault,
                                vda->bitstream,
                                vda->bitstream_size);

     status = VDADecoderDecode(vda_ctx->decoder, 0, coded_frame, NULL);

     if (status == kVDADecoderNoErr)
         status = VDADecoderFlush(vda_ctx->decoder, flush_flags);

     CFRelease(coded_frame);

     if (status != kVDADecoderNoErr) {
         av_log(avctx, AV_LOG_ERROR, "Failed to decode frame (%d)\n", status);
         return AVERROR_UNKNOWN;
     }

     if (vda->frame) {
         av_buffer_unref(&frame->buf[0]);

         frame->buf[0] = av_buffer_create((uint8_t*)vda->frame,
                                          sizeof(vda->frame),
                                          release_buffer, NULL,
                                          AV_BUFFER_FLAG_READONLY);
         if (!frame->buf)
             return AVERROR(ENOMEM);

         frame->data[3] = (uint8_t*)vda->frame;
         vda->frame = NULL;
     }

     return 0;
 }

 int ff_vda_default_init(AVCodecContext *avctx)
 {
     AVVDAContext *vda_ctx = avctx->hwaccel_context;
     OSStatus status = kVDADecoderNoErr;
     CFNumberRef height;
     CFNumberRef width;
     CFNumberRef format;
     CFDataRef avc_data;
     CFMutableDictionaryRef config_info;
     CFMutableDictionaryRef buffer_attributes;
     CFMutableDictionaryRef io_surface_properties;
     CFNumberRef cv_pix_fmt;
     int32_t fmt = 'avc1', pix_fmt = kCVPixelFormatType_422YpCbCr8;

     // kCVPixelFormatType_420YpCbCr8Planar;

     /* Each VCL NAL in the bitstream sent to the decoder
      * is preceded by a 4 bytes length header.
      * Change the avcC atom header if needed, to signal headers of 4 bytes. */
     if (avctx->extradata_size >= 4 && (avctx->extradata[4] & 0x03) != 0x03) {
         uint8_t *rw_extradata;

         if (!(rw_extradata = av_malloc(avctx->extradata_size)))
             return AVERROR(ENOMEM);

         memcpy(rw_extradata, avctx->extradata, avctx->extradata_size);

         rw_extradata[4] |= 0x03;

         avc_data = CFDataCreate(kCFAllocatorDefault, rw_extradata, avctx->extradata_size);

         av_freep(&rw_extradata);
     } else {
         avc_data = CFDataCreate(kCFAllocatorDefault,
                                 avctx->extradata, avctx->extradata_size);
     }

     config_info = CFDictionaryCreateMutable(kCFAllocatorDefault,
                                             4,
                                             &kCFTypeDictionaryKeyCallBacks,
                                             &kCFTypeDictionaryValueCallBacks);

     height = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &avctx->height);
     width  = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &avctx->width);
     format = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &fmt);
     CFDictionarySetValue(config_info, kVDADecoderConfiguration_Height, height);
     CFDictionarySetValue(config_info, kVDADecoderConfiguration_Width, width);
     CFDictionarySetValue(config_info, kVDADecoderConfiguration_avcCData, avc_data);
     CFDictionarySetValue(config_info, kVDADecoderConfiguration_SourceFormat, format);

     buffer_attributes = CFDictionaryCreateMutable(kCFAllocatorDefault,
                                                   2,
                                                   &kCFTypeDictionaryKeyCallBacks,
                                                   &kCFTypeDictionaryValueCallBacks);
     io_surface_properties = CFDictionaryCreateMutable(kCFAllocatorDefault,
                                                       0,
                                                       &kCFTypeDictionaryKeyCallBacks,
                                                       &kCFTypeDictionaryValueCallBacks);
     cv_pix_fmt      = CFNumberCreate(kCFAllocatorDefault,
                                      kCFNumberSInt32Type,
                                      &pix_fmt);

     CFDictionarySetValue(buffer_attributes,
                          kCVPixelBufferPixelFormatTypeKey,
                          cv_pix_fmt);
     CFDictionarySetValue(buffer_attributes,
                          kCVPixelBufferIOSurfacePropertiesKey,
                          io_surface_properties);

     status = VDADecoderCreate(config_info,
                               buffer_attributes,
                               (VDADecoderOutputCallback *)ff_vda_output_callback,
                               avctx,
                               &vda_ctx->decoder);

     CFRelease(format);
     CFRelease(height);
     CFRelease(width);
     CFRelease(avc_data);
     CFRelease(config_info);
     CFRelease(cv_pix_fmt);
     CFRelease(io_surface_properties);
     CFRelease(buffer_attributes);

     if (status != kVDADecoderNoErr) {
         av_log(avctx, AV_LOG_ERROR, "Cannot initialize VDA %d\n", status);
     }

     switch (status) {
     case kVDADecoderHardwareNotSupportedErr:
     case kVDADecoderFormatNotSupportedErr:
         return AVERROR(ENOSYS);
     case kVDADecoderConfigurationError:
         return AVERROR(EINVAL);
     case kVDADecoderDecoderFailedErr:
         return AVERROR_INVALIDDATA;
     case kVDADecoderNoErr:
         return 0;
     default:
         return AVERROR_UNKNOWN;
     }
 }

 static int vda_h264_alloc_frame(AVCodecContext *avctx, AVFrame *frame)
 {
     frame->width  = avctx->width;
     frame->height = avctx->height;
     frame->format = avctx->pix_fmt;
     frame->buf[0] = av_buffer_alloc(1);

     if (!frame->buf[0])
         return AVERROR(ENOMEM);
     return 0;
 }

 AVHWAccel ff_h264_vda_hwaccel = {
     .name           = "h264_vda",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_H264,
     .pix_fmt        = AV_PIX_FMT_VDA,
     .alloc_frame    = vda_h264_alloc_frame,
     .start_frame    = vda_h264_start_frame,
     .decode_slice   = vda_h264_decode_slice,
     .end_frame      = vda_h264_end_frame,
     .uninit         = vda_h264_uninit,
     .priv_data_size = sizeof(VDAContext),
 };
	/*
	* VDA H264 HW acceleration.
	*
	* copyright (c) 2011 Sebastien Zwickert
	*
	* 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 <CoreFoundation/CFDictionary.h>
	#include <CoreFoundation/CFNumber.h>
	#include <CoreFoundation/CFData.h>

	#include "vda.h"
	#include "libavutil/avutil.h"
	#include "h264.h"

	struct vda_buffer {
	CVPixelBufferRef cv_buffer;
	};
	#include "internal.h"
	#include "vda_internal.h"

	typedef struct VDAContext {
	// The current bitstream buffer.
	uint8_t *bitstream;

	// The current size of the bitstream.
	int bitstream_size;

	// The reference size used for fast reallocation.
	int allocated_size;

	CVImageBufferRef frame;
	} VDAContext;

	/* Decoder callback that adds the vda frame to the queue in display order. */
	static void vda_decoder_callback(void *vda_hw_ctx,
	CFDictionaryRef user_info,
	OSStatus status,
	uint32_t infoFlags,
	CVImageBufferRef image_buffer)
	{
	struct vda_context *vda_ctx = vda_hw_ctx;

	if (infoFlags & kVDADecodeInfo_FrameDropped)
	vda_ctx->cv_buffer = NULL;

	if (!image_buffer)
	return;

	if (vda_ctx->cv_pix_fmt_type != CVPixelBufferGetPixelFormatType(image_buffer))
	return;

	vda_ctx->cv_buffer = CVPixelBufferRetain(image_buffer);
	}

	static int vda_sync_decode(VDAContext ctx, struct vda_context vda_ctx)
	{
	OSStatus status;
	CFDataRef coded_frame;
	uint32_t flush_flags = 1 << 0; ///< kVDADecoderFlush_emitFrames

	coded_frame = CFDataCreate(kCFAllocatorDefault,
	ctx->bitstream,
	ctx->bitstream_size);

	status = VDADecoderDecode(vda_ctx->decoder, 0, coded_frame, NULL);

	if (kVDADecoderNoErr == status)
	status = VDADecoderFlush(vda_ctx->decoder, flush_flags);

	CFRelease(coded_frame);

	return status;
	}


	static int vda_old_h264_start_frame(AVCodecContext *avctx,
	av_unused const uint8_t *buffer,
	av_unused uint32_t size)
	{
	VDAContext *vda = avctx->internal->hwaccel_priv_data;
	struct vda_context *vda_ctx = avctx->hwaccel_context;

	if (!vda_ctx->decoder)
	return -1;

	vda->bitstream_size = 0;

	return 0;
	}

	static int vda_old_h264_decode_slice(AVCodecContext *avctx,
	const uint8_t *buffer,
	uint32_t size)
	{
	VDAContext *vda = avctx->internal->hwaccel_priv_data;
	struct vda_context *vda_ctx = avctx->hwaccel_context;
	void *tmp;

	if (!vda_ctx->decoder)
	return -1;

	tmp = av_fast_realloc(vda->bitstream,
	&vda->allocated_size,
	vda->bitstream_size + size + 4);
	if (!tmp)
	return AVERROR(ENOMEM);

	vda->bitstream = tmp;

	AV_WB32(vda->bitstream + vda->bitstream_size, size);
	memcpy(vda->bitstream + vda->bitstream_size + 4, buffer, size);

	vda->bitstream_size += size + 4;

	return 0;
	}

	static void vda_h264_release_buffer(void opaque, uint8_t data)
	{
	struct vda_buffer *context = opaque;
	CVPixelBufferRelease(context->cv_buffer);
	av_free(context);
	}

	static int vda_old_h264_end_frame(AVCodecContext *avctx)
	{
	H264Context *h = avctx->priv_data;
	VDAContext *vda = avctx->internal->hwaccel_priv_data;
	struct vda_context *vda_ctx = avctx->hwaccel_context;
	AVFrame *frame = &h->cur_pic_ptr->f;
	struct vda_buffer *context;
	AVBufferRef *buffer;
	int status;

	if (!vda_ctx->decoder \|\| !vda->bitstream)
	return -1;

	status = vda_sync_decode(vda, vda_ctx);
	frame->data[3] = (void*)vda_ctx->cv_buffer;

	if (status)
	av_log(avctx, AV_LOG_ERROR, "Failed to decode frame (%d)\n", status);

	if (!vda_ctx->use_ref_buffer \|\| status)
	return status;

	context = av_mallocz(sizeof(*context));
	buffer = av_buffer_create(NULL, 0, vda_h264_release_buffer, context, 0);
	if (!context \|\| !buffer) {
	CVPixelBufferRelease(vda_ctx->cv_buffer);
	av_free(context);
	return -1;
	}

	context->cv_buffer = vda_ctx->cv_buffer;
	frame->buf[3] = buffer;

	return status;
	}

	int ff_vda_create_decoder(struct vda_context *vda_ctx,
	uint8_t *extradata,
	int extradata_size)
	{
	OSStatus status;
	CFNumberRef height;
	CFNumberRef width;
	CFNumberRef format;
	CFDataRef avc_data;
	CFMutableDictionaryRef config_info;
	CFMutableDictionaryRef buffer_attributes;
	CFMutableDictionaryRef io_surface_properties;
	CFNumberRef cv_pix_fmt;

	vda_ctx->priv_bitstream = NULL;
	vda_ctx->priv_allocated_size = 0;

	/* Each VCL NAL in the bitstream sent to the decoder
	* is preceded by a 4 bytes length header.
	* Change the avcC atom header if needed, to signal headers of 4 bytes. */
	if (extradata_size >= 4 && (extradata[4] & 0x03) != 0x03) {
	uint8_t *rw_extradata;

	if (!(rw_extradata = av_malloc(extradata_size)))
	return AVERROR(ENOMEM);

	memcpy(rw_extradata, extradata, extradata_size);

	rw_extradata[4] \|= 0x03;

	avc_data = CFDataCreate(kCFAllocatorDefault, rw_extradata, extradata_size);

	av_freep(&rw_extradata);
	} else {
	avc_data = CFDataCreate(kCFAllocatorDefault, extradata, extradata_size);
	}

	config_info = CFDictionaryCreateMutable(kCFAllocatorDefault,
	4,
	&kCFTypeDictionaryKeyCallBacks,
	&kCFTypeDictionaryValueCallBacks);

	height = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &vda_ctx->height);
	width = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &vda_ctx->width);
	format = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &vda_ctx->format);

	CFDictionarySetValue(config_info, kVDADecoderConfiguration_Height, height);
	CFDictionarySetValue(config_info, kVDADecoderConfiguration_Width, width);
	CFDictionarySetValue(config_info, kVDADecoderConfiguration_SourceFormat, format);
	CFDictionarySetValue(config_info, kVDADecoderConfiguration_avcCData, avc_data);

	buffer_attributes = CFDictionaryCreateMutable(kCFAllocatorDefault,
	2,
	&kCFTypeDictionaryKeyCallBacks,
	&kCFTypeDictionaryValueCallBacks);
	io_surface_properties = CFDictionaryCreateMutable(kCFAllocatorDefault,
	0,
	&kCFTypeDictionaryKeyCallBacks,
	&kCFTypeDictionaryValueCallBacks);
	cv_pix_fmt = CFNumberCreate(kCFAllocatorDefault,
	kCFNumberSInt32Type,
	&vda_ctx->cv_pix_fmt_type);
	CFDictionarySetValue(buffer_attributes,
	kCVPixelBufferPixelFormatTypeKey,
	cv_pix_fmt);
	CFDictionarySetValue(buffer_attributes,
	kCVPixelBufferIOSurfacePropertiesKey,
	io_surface_properties);

	status = VDADecoderCreate(config_info,
	buffer_attributes,
	(VDADecoderOutputCallback *)vda_decoder_callback,
	vda_ctx,
	&vda_ctx->decoder);

	CFRelease(height);
	CFRelease(width);
	CFRelease(format);
	CFRelease(avc_data);
	CFRelease(config_info);
	CFRelease(io_surface_properties);
	CFRelease(cv_pix_fmt);
	CFRelease(buffer_attributes);

	return status;
	}

	int ff_vda_destroy_decoder(struct vda_context *vda_ctx)
	{
	OSStatus status = kVDADecoderNoErr;

	if (vda_ctx->decoder)
	status = VDADecoderDestroy(vda_ctx->decoder);

	return status;
	}

	static int vda_h264_uninit(AVCodecContext *avctx)
	{
	VDAContext *vda = avctx->internal->hwaccel_priv_data;
	if (vda) {
	av_freep(&vda->bitstream);
	if (vda->frame)
	CVPixelBufferRelease(vda->frame);
	}
	return 0;
	}

	AVHWAccel ff_h264_vda_old_hwaccel = {
	.name = "h264_vda",
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_H264,
	.pix_fmt = AV_PIX_FMT_VDA_VLD,
	.start_frame = vda_old_h264_start_frame,
	.decode_slice = vda_old_h264_decode_slice,
	.end_frame = vda_old_h264_end_frame,
	.uninit = vda_h264_uninit,
	.priv_data_size = sizeof(VDAContext),
	};

	void ff_vda_output_callback(void *opaque,
	CFDictionaryRef user_info,
	OSStatus status,
	uint32_t infoFlags,
	CVImageBufferRef image_buffer)
	{
	AVCodecContext *ctx = opaque;
	VDAContext *vda = ctx->internal->hwaccel_priv_data;


	if (vda->frame) {
	CVPixelBufferRelease(vda->frame);
	vda->frame = NULL;
	}

	if (!image_buffer)
	return;

	vda->frame = CVPixelBufferRetain(image_buffer);
	}

	static int vda_h264_start_frame(AVCodecContext *avctx,
	const uint8_t *buffer,
	uint32_t size)
	{
	VDAContext *vda = avctx->internal->hwaccel_priv_data;

	vda->bitstream_size = 0;

	return 0;
	}

	static int vda_h264_decode_slice(AVCodecContext *avctx,
	const uint8_t *buffer,
	uint32_t size)
	{
	VDAContext *vda = avctx->internal->hwaccel_priv_data;
	void *tmp;

	tmp = av_fast_realloc(vda->bitstream,
	&vda->allocated_size,
	vda->bitstream_size + size + 4);
	if (!tmp)
	return AVERROR(ENOMEM);

	vda->bitstream = tmp;

	AV_WB32(vda->bitstream + vda->bitstream_size, size);
	memcpy(vda->bitstream + vda->bitstream_size + 4, buffer, size);

	vda->bitstream_size += size + 4;

	return 0;
	}

	static void release_buffer(void opaque, uint8_t data)
	{
	CVImageBufferRef frame = (CVImageBufferRef)data;
	CVPixelBufferRelease(frame);
	}

	static int vda_h264_end_frame(AVCodecContext *avctx)
	{
	H264Context *h = avctx->priv_data;
	VDAContext *vda = avctx->internal->hwaccel_priv_data;
	AVVDAContext *vda_ctx = avctx->hwaccel_context;
	AVFrame *frame = &h->cur_pic_ptr->f;
	uint32_t flush_flags = 1 << 0; ///< kVDADecoderFlush_emitFrames
	CFDataRef coded_frame;
	OSStatus status;

	if (!vda->bitstream_size)
	return AVERROR_INVALIDDATA;


	coded_frame = CFDataCreate(kCFAllocatorDefault,
	vda->bitstream,
	vda->bitstream_size);

	status = VDADecoderDecode(vda_ctx->decoder, 0, coded_frame, NULL);

	if (status == kVDADecoderNoErr)
	status = VDADecoderFlush(vda_ctx->decoder, flush_flags);

	CFRelease(coded_frame);

	if (status != kVDADecoderNoErr) {
	av_log(avctx, AV_LOG_ERROR, "Failed to decode frame (%d)\n", status);
	return AVERROR_UNKNOWN;
	}

	if (vda->frame) {
	av_buffer_unref(&frame->buf[0]);

	frame->buf[0] = av_buffer_create((uint8_t*)vda->frame,
	sizeof(vda->frame),
	release_buffer, NULL,
	AV_BUFFER_FLAG_READONLY);
	if (!frame->buf)
	return AVERROR(ENOMEM);

	frame->data[3] = (uint8_t*)vda->frame;
	vda->frame = NULL;
	}

	return 0;
	}

	int ff_vda_default_init(AVCodecContext *avctx)
	{
	AVVDAContext *vda_ctx = avctx->hwaccel_context;
	OSStatus status = kVDADecoderNoErr;
	CFNumberRef height;
	CFNumberRef width;
	CFNumberRef format;
	CFDataRef avc_data;
	CFMutableDictionaryRef config_info;
	CFMutableDictionaryRef buffer_attributes;
	CFMutableDictionaryRef io_surface_properties;
	CFNumberRef cv_pix_fmt;
	int32_t fmt = 'avc1', pix_fmt = kCVPixelFormatType_422YpCbCr8;

	// kCVPixelFormatType_420YpCbCr8Planar;

	/* Each VCL NAL in the bitstream sent to the decoder
	* is preceded by a 4 bytes length header.
	* Change the avcC atom header if needed, to signal headers of 4 bytes. */
	if (avctx->extradata_size >= 4 && (avctx->extradata[4] & 0x03) != 0x03) {
	uint8_t *rw_extradata;

	if (!(rw_extradata = av_malloc(avctx->extradata_size)))
	return AVERROR(ENOMEM);

	memcpy(rw_extradata, avctx->extradata, avctx->extradata_size);

	rw_extradata[4] \|= 0x03;

	avc_data = CFDataCreate(kCFAllocatorDefault, rw_extradata, avctx->extradata_size);

	av_freep(&rw_extradata);
	} else {
	avc_data = CFDataCreate(kCFAllocatorDefault,
	avctx->extradata, avctx->extradata_size);
	}

	config_info = CFDictionaryCreateMutable(kCFAllocatorDefault,
	4,
	&kCFTypeDictionaryKeyCallBacks,
	&kCFTypeDictionaryValueCallBacks);

	height = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &avctx->height);
	width = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &avctx->width);
	format = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt32Type, &fmt);
	CFDictionarySetValue(config_info, kVDADecoderConfiguration_Height, height);
	CFDictionarySetValue(config_info, kVDADecoderConfiguration_Width, width);
	CFDictionarySetValue(config_info, kVDADecoderConfiguration_avcCData, avc_data);
	CFDictionarySetValue(config_info, kVDADecoderConfiguration_SourceFormat, format);

	buffer_attributes = CFDictionaryCreateMutable(kCFAllocatorDefault,
	2,
	&kCFTypeDictionaryKeyCallBacks,
	&kCFTypeDictionaryValueCallBacks);
	io_surface_properties = CFDictionaryCreateMutable(kCFAllocatorDefault,
	0,
	&kCFTypeDictionaryKeyCallBacks,
	&kCFTypeDictionaryValueCallBacks);
	cv_pix_fmt = CFNumberCreate(kCFAllocatorDefault,
	kCFNumberSInt32Type,
	&pix_fmt);

	CFDictionarySetValue(buffer_attributes,
	kCVPixelBufferPixelFormatTypeKey,
	cv_pix_fmt);
	CFDictionarySetValue(buffer_attributes,
	kCVPixelBufferIOSurfacePropertiesKey,
	io_surface_properties);

	status = VDADecoderCreate(config_info,
	buffer_attributes,
	(VDADecoderOutputCallback *)ff_vda_output_callback,
	avctx,
	&vda_ctx->decoder);

	CFRelease(format);
	CFRelease(height);
	CFRelease(width);
	CFRelease(avc_data);
	CFRelease(config_info);
	CFRelease(cv_pix_fmt);
	CFRelease(io_surface_properties);
	CFRelease(buffer_attributes);

	if (status != kVDADecoderNoErr) {
	av_log(avctx, AV_LOG_ERROR, "Cannot initialize VDA %d\n", status);
	}

	switch (status) {
	case kVDADecoderHardwareNotSupportedErr:
	case kVDADecoderFormatNotSupportedErr:
	return AVERROR(ENOSYS);
	case kVDADecoderConfigurationError:
	return AVERROR(EINVAL);
	case kVDADecoderDecoderFailedErr:
	return AVERROR_INVALIDDATA;
	case kVDADecoderNoErr:
	return 0;
	default:
	return AVERROR_UNKNOWN;
	}
	}

	static int vda_h264_alloc_frame(AVCodecContext avctx, AVFrame frame)
	{
	frame->width = avctx->width;
	frame->height = avctx->height;
	frame->format = avctx->pix_fmt;
	frame->buf[0] = av_buffer_alloc(1);

	if (!frame->buf[0])
	return AVERROR(ENOMEM);
	return 0;
	}

	AVHWAccel ff_h264_vda_hwaccel = {
	.name = "h264_vda",
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_H264,
	.pix_fmt = AV_PIX_FMT_VDA,
	.alloc_frame = vda_h264_alloc_frame,
	.start_frame = vda_h264_start_frame,
	.decode_slice = vda_h264_decode_slice,
	.end_frame = vda_h264_end_frame,
	.uninit = vda_h264_uninit,
	.priv_data_size = sizeof(VDAContext),
	};