/*
  * Copyright (c) 2012, Xidorn Quan
  *
  * 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
  */
 
 /**
  * @file
  * H.264 decoder via VDA
  * @author Xidorn Quan <quanxunzhen@gmail.com>
  */
 
 #include <string.h>
 #include <CoreFoundation/CoreFoundation.h>
 
 #include "vda.h"

 #include "h264dec.h"

 #include "avcodec.h"
 
 #ifndef kCFCoreFoundationVersionNumber10_7
 #define kCFCoreFoundationVersionNumber10_7      635.00
 #endif
 
 extern AVCodec ff_h264_decoder, ff_h264_vda_decoder;
 

 static const enum AVPixelFormat vda_pixfmts_prior_10_7[] = {
     AV_PIX_FMT_UYVY422,
     AV_PIX_FMT_YUV420P,
     AV_PIX_FMT_NONE

 };
 

 static const enum AVPixelFormat vda_pixfmts[] = {
     AV_PIX_FMT_UYVY422,
     AV_PIX_FMT_YUYV422,
     AV_PIX_FMT_NV12,
     AV_PIX_FMT_YUV420P,
     AV_PIX_FMT_NONE

 };
 
 typedef struct {
     H264Context h264ctx;
     int h264_initialized;
     struct vda_context vda_ctx;

     enum AVPixelFormat pix_fmt;

 
     /* for backing-up fields set by user.
      * we have to gain full control of such fields here */
     void *hwaccel_context;
     enum AVPixelFormat (*get_format)(struct AVCodecContext *s, const enum AVPixelFormat * fmt);
     int (*get_buffer2)(struct AVCodecContext *s, AVFrame *frame, int flags);

 } VDADecoderContext;
 

 static enum AVPixelFormat get_format(struct AVCodecContext *avctx,
         const enum AVPixelFormat *fmt)

 {

     return AV_PIX_FMT_VDA_VLD;

 }
 

 typedef struct {
     CVPixelBufferRef cv_buffer;
 } VDABufferContext;
 
 static void release_buffer(void *opaque, uint8_t *data)

 {

     VDABufferContext *context = opaque;
     CVPixelBufferUnlockBaseAddress(context->cv_buffer, 0);
     CVPixelBufferRelease(context->cv_buffer);
     av_free(context);

 }
 

 static int get_buffer2(AVCodecContext *avctx, AVFrame *pic, int flag)

 {

     VDABufferContext *context = av_mallocz(sizeof(VDABufferContext));
     AVBufferRef *buffer = av_buffer_create(NULL, 0, release_buffer, context, 0);
     if (!context || !buffer) {
         av_free(context);
         return AVERROR(ENOMEM);
     }

     pic->buf[0] = buffer;
     pic->data[0] = (void *)1;
     return 0;

 }
 

 static inline void set_context(AVCodecContext *avctx)
 {
     VDADecoderContext *ctx = avctx->priv_data;
     ctx->hwaccel_context = avctx->hwaccel_context;
     avctx->hwaccel_context = &ctx->vda_ctx;
     ctx->get_format = avctx->get_format;
     avctx->get_format = get_format;
     ctx->get_buffer2 = avctx->get_buffer2;
     avctx->get_buffer2 = get_buffer2;
 }
 
 static inline void restore_context(AVCodecContext *avctx)
 {
     VDADecoderContext *ctx = avctx->priv_data;
     avctx->hwaccel_context = ctx->hwaccel_context;
     avctx->get_format = ctx->get_format;
     avctx->get_buffer2 = ctx->get_buffer2;
 }
 

 static int vdadec_decode(AVCodecContext *avctx,

         void *data, int *got_frame, AVPacket *avpkt)

 {
     VDADecoderContext *ctx = avctx->priv_data;
     AVFrame *pic = data;
     int ret;
 

     set_context(avctx);

     ret = ff_h264_decoder.decode(avctx, data, got_frame, avpkt);

     restore_context(avctx);

     if (*got_frame) {

         AVBufferRef *buffer = pic->buf[0];
         VDABufferContext *context = av_buffer_get_opaque(buffer);

         CVPixelBufferRef cv_buffer = (CVPixelBufferRef)pic->data[3];

 
         CVPixelBufferRetain(cv_buffer);

         CVPixelBufferLockBaseAddress(cv_buffer, 0);

         context->cv_buffer = cv_buffer;

         pic->format = ctx->pix_fmt;
         if (CVPixelBufferIsPlanar(cv_buffer)) {
             int i, count = CVPixelBufferGetPlaneCount(cv_buffer);
             av_assert0(count < 4);
             for (i = 0; i < count; i++) {
                 pic->data[i] = CVPixelBufferGetBaseAddressOfPlane(cv_buffer, i);
                 pic->linesize[i] = CVPixelBufferGetBytesPerRowOfPlane(cv_buffer, i);
             }
         } else {
             pic->data[0] = CVPixelBufferGetBaseAddress(cv_buffer);
             pic->linesize[0] = CVPixelBufferGetBytesPerRow(cv_buffer);
         }
     }
     avctx->pix_fmt = ctx->pix_fmt;
 
     return ret;
 }
 
 static av_cold int vdadec_close(AVCodecContext *avctx)
 {
     VDADecoderContext *ctx = avctx->priv_data;
     /* release buffers and decoder */
     ff_vda_destroy_decoder(&ctx->vda_ctx);
     /* close H.264 decoder */

     if (ctx->h264_initialized) {
         set_context(avctx);

         ff_h264_decoder.close(avctx);

         restore_context(avctx);
     }

     return 0;
 }
 
 static av_cold int vdadec_init(AVCodecContext *avctx)
 {
     VDADecoderContext *ctx = avctx->priv_data;
     struct vda_context *vda_ctx = &ctx->vda_ctx;
     OSStatus status;

     int ret, i;

 
     ctx->h264_initialized = 0;
 
     /* init pix_fmts of codec */
     if (!ff_h264_vda_decoder.pix_fmts) {
         if (kCFCoreFoundationVersionNumber < kCFCoreFoundationVersionNumber10_7)
             ff_h264_vda_decoder.pix_fmts = vda_pixfmts_prior_10_7;
         else
             ff_h264_vda_decoder.pix_fmts = vda_pixfmts;
     }
 
     /* init vda */
     memset(vda_ctx, 0, sizeof(struct vda_context));
     vda_ctx->width = avctx->width;
     vda_ctx->height = avctx->height;
     vda_ctx->format = 'avc1';
     vda_ctx->use_sync_decoding = 1;

     vda_ctx->use_ref_buffer = 1;

     ctx->pix_fmt = avctx->get_format(avctx, avctx->codec->pix_fmts);
     switch (ctx->pix_fmt) {

     case AV_PIX_FMT_UYVY422:

         vda_ctx->cv_pix_fmt_type = '2vuy';
         break;

     case AV_PIX_FMT_YUYV422:

         vda_ctx->cv_pix_fmt_type = 'yuvs';
         break;

     case AV_PIX_FMT_NV12:

         vda_ctx->cv_pix_fmt_type = '420v';
         break;

     case AV_PIX_FMT_YUV420P:

         vda_ctx->cv_pix_fmt_type = 'y420';
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format: %d\n", avctx->pix_fmt);
         goto failed;
     }
     status = ff_vda_create_decoder(vda_ctx,
                                    avctx->extradata, avctx->extradata_size);
     if (status != kVDADecoderNoErr) {
         av_log(avctx, AV_LOG_ERROR,
                 "Failed to init VDA decoder: %d.\n", status);
         goto failed;
     }
 
     /* init H.264 decoder */

     set_context(avctx);

     ret = ff_h264_decoder.init(avctx);

     restore_context(avctx);

     if (ret < 0) {
         av_log(avctx, AV_LOG_ERROR, "Failed to open H.264 decoder.\n");
         goto failed;
     }
     ctx->h264_initialized = 1;
 

     for (i = 0; i < MAX_SPS_COUNT; i++) {

         const SPS *sps = ctx->h264ctx.ps.sps_list[i] ? (const SPS*)ctx->h264ctx.ps.sps_list[i]->data : NULL;

         if (sps && (sps->bit_depth_luma != 8 ||
                 sps->chroma_format_idc == 2 ||
                 sps->chroma_format_idc == 3)) {
             av_log(avctx, AV_LOG_ERROR, "Format is not supported.\n");
             goto failed;
         }
     }
 

     return 0;
 
 failed:
     vdadec_close(avctx);
     return -1;
 }
 
 static void vdadec_flush(AVCodecContext *avctx)
 {

     set_context(avctx);
     ff_h264_decoder.flush(avctx);
     restore_context(avctx);

 }
 
 AVCodec ff_h264_vda_decoder = {
     .name           = "h264_vda",
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_H264,
     .priv_data_size = sizeof(VDADecoderContext),
     .init           = vdadec_init,
     .close          = vdadec_close,
     .decode         = vdadec_decode,

     .capabilities   = AV_CODEC_CAP_DELAY,

     .flush          = vdadec_flush,
     .long_name      = NULL_IF_CONFIG_SMALL("H.264 (VDA acceleration)"),
 };