libavcodec/utvideoenc.c - nest-android-app/ffmpeg - Git at Google

 /*
  * Ut Video encoder
  * Copyright (c) 2012 Jan Ekström
  *
  * 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
  * Ut Video encoder
  */

 #include "libavutil/imgutils.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/opt.h"

 #include "avcodec.h"
 #include "internal.h"
 #include "bswapdsp.h"
 #include "bytestream.h"
 #include "put_bits.h"
 #include "huffyuvencdsp.h"
 #include "mathops.h"
 #include "utvideo.h"
 #include "huffman.h"

 /* Compare huffentry symbols */
 static int huff_cmp_sym(const void *a, const void *b)
 {
     const HuffEntry *aa = a, *bb = b;
     return aa->sym - bb->sym;
 }

 static av_cold int utvideo_encode_close(AVCodecContext *avctx)
 {
     UtvideoContext *c = avctx->priv_data;
     int i;

     av_freep(&c->slice_bits);
     for (i = 0; i < 4; i++)
         av_freep(&c->slice_buffer[i]);

     return 0;
 }

 static av_cold int utvideo_encode_init(AVCodecContext *avctx)
 {
     UtvideoContext *c = avctx->priv_data;
     int i, subsampled_height;
     uint32_t original_format;

     c->avctx           = avctx;
     c->frame_info_size = 4;
     c->slice_stride    = FFALIGN(avctx->width, 32);

     switch (avctx->pix_fmt) {
     case AV_PIX_FMT_RGB24:
         c->planes        = 3;
         avctx->codec_tag = MKTAG('U', 'L', 'R', 'G');
         original_format  = UTVIDEO_RGB;
         break;
     case AV_PIX_FMT_RGBA:
         c->planes        = 4;
         avctx->codec_tag = MKTAG('U', 'L', 'R', 'A');
         original_format  = UTVIDEO_RGBA;
         break;
     case AV_PIX_FMT_YUV420P:
         if (avctx->width & 1 || avctx->height & 1) {
             av_log(avctx, AV_LOG_ERROR,
                    "4:2:0 video requires even width and height.\n");
             return AVERROR_INVALIDDATA;
         }
         c->planes        = 3;
         if (avctx->colorspace == AVCOL_SPC_BT709)
             avctx->codec_tag = MKTAG('U', 'L', 'H', '0');
         else
             avctx->codec_tag = MKTAG('U', 'L', 'Y', '0');
         original_format  = UTVIDEO_420;
         break;
     case AV_PIX_FMT_YUV422P:
         if (avctx->width & 1) {
             av_log(avctx, AV_LOG_ERROR,
                    "4:2:2 video requires even width.\n");
             return AVERROR_INVALIDDATA;
         }
         c->planes        = 3;
         if (avctx->colorspace == AVCOL_SPC_BT709)
             avctx->codec_tag = MKTAG('U', 'L', 'H', '2');
         else
             avctx->codec_tag = MKTAG('U', 'L', 'Y', '2');
         original_format  = UTVIDEO_422;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unknown pixel format: %d\n",
                avctx->pix_fmt);
         return AVERROR_INVALIDDATA;
     }

     ff_bswapdsp_init(&c->bdsp);
     ff_huffyuvencdsp_init(&c->hdsp);

 #if FF_API_PRIVATE_OPT
 FF_DISABLE_DEPRECATION_WARNINGS
     /* Check the prediction method, and error out if unsupported */
     if (avctx->prediction_method < 0 || avctx->prediction_method > 4) {
         av_log(avctx, AV_LOG_WARNING,
                "Prediction method %d is not supported in Ut Video.\n",
                avctx->prediction_method);
         return AVERROR_OPTION_NOT_FOUND;
     }

     if (avctx->prediction_method == FF_PRED_PLANE) {
         av_log(avctx, AV_LOG_ERROR,
                "Plane prediction is not supported in Ut Video.\n");
         return AVERROR_OPTION_NOT_FOUND;
     }

     /* Convert from libavcodec prediction type to Ut Video's */
     if (avctx->prediction_method)
         c->frame_pred = ff_ut_pred_order[avctx->prediction_method];
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

     if (c->frame_pred == PRED_GRADIENT) {
         av_log(avctx, AV_LOG_ERROR, "Gradient prediction is not supported.\n");
         return AVERROR_OPTION_NOT_FOUND;
     }

     /*
      * Check the asked slice count for obviously invalid
      * values (> 256 or negative).
      */
     if (avctx->slices > 256 || avctx->slices < 0) {
         av_log(avctx, AV_LOG_ERROR,
                "Slice count %d is not supported in Ut Video (theoretical range is 0-256).\n",
                avctx->slices);
         return AVERROR(EINVAL);
     }

     /* Check that the slice count is not larger than the subsampled height */
     subsampled_height = avctx->height >> av_pix_fmt_desc_get(avctx->pix_fmt)->log2_chroma_h;
     if (avctx->slices > subsampled_height) {
         av_log(avctx, AV_LOG_ERROR,
                "Slice count %d is larger than the subsampling-applied height %d.\n",
                avctx->slices, subsampled_height);
         return AVERROR(EINVAL);
     }

     /* extradata size is 4 * 32bit */
     avctx->extradata_size = 16;

     avctx->extradata = av_mallocz(avctx->extradata_size +
                                   AV_INPUT_BUFFER_PADDING_SIZE);

     if (!avctx->extradata) {
         av_log(avctx, AV_LOG_ERROR, "Could not allocate extradata.\n");
         utvideo_encode_close(avctx);
         return AVERROR(ENOMEM);
     }

     for (i = 0; i < c->planes; i++) {
         c->slice_buffer[i] = av_malloc(c->slice_stride * (avctx->height + 2) +
                                        AV_INPUT_BUFFER_PADDING_SIZE);
         if (!c->slice_buffer[i]) {
             av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer 1.\n");
             utvideo_encode_close(avctx);
             return AVERROR(ENOMEM);
         }
     }

     /*
      * Set the version of the encoder.
      * Last byte is "implementation ID", which is
      * obtained from the creator of the format.
      * Libavcodec has been assigned with the ID 0xF0.
      */
     AV_WB32(avctx->extradata, MKTAG(1, 0, 0, 0xF0));

     /*
      * Set the "original format"
      * Not used for anything during decoding.
      */
     AV_WL32(avctx->extradata + 4, original_format);

     /* Write 4 as the 'frame info size' */
     AV_WL32(avctx->extradata + 8, c->frame_info_size);

     /*
      * Set how many slices are going to be used.
      * By default uses multiple slices depending on the subsampled height.
      * This enables multithreading in the official decoder.
      */
     if (!avctx->slices) {
         c->slices = subsampled_height / 120;

         if (!c->slices)
             c->slices = 1;
         else if (c->slices > 256)
             c->slices = 256;
     } else {
         c->slices = avctx->slices;
     }

     /* Set compression mode */
     c->compression = COMP_HUFF;

     /*
      * Set the encoding flags:
      * - Slice count minus 1
      * - Interlaced encoding mode flag, set to zero for now.
      * - Compression mode (none/huff)
      * And write the flags.
      */
     c->flags  = (c->slices - 1) << 24;
     c->flags |= 0 << 11; // bit field to signal interlaced encoding mode
     c->flags |= c->compression;

     AV_WL32(avctx->extradata + 12, c->flags);

     return 0;
 }

 static void mangle_rgb_planes(uint8_t *dst[4], int dst_stride, uint8_t *src,
                               int step, int stride, int width, int height)
 {
     int i, j;
     int k = 2 * dst_stride;
     unsigned int g;

     for (j = 0; j < height; j++) {
         if (step == 3) {
             for (i = 0; i < width * step; i += step) {
                 g         = src[i + 1];
                 dst[0][k] = g;
                 g        += 0x80;
                 dst[1][k] = src[i + 2] - g;
                 dst[2][k] = src[i + 0] - g;
                 k++;
             }
         } else {
             for (i = 0; i < width * step; i += step) {
                 g         = src[i + 1];
                 dst[0][k] = g;
                 g        += 0x80;
                 dst[1][k] = src[i + 2] - g;
                 dst[2][k] = src[i + 0] - g;
                 dst[3][k] = src[i + 3];
                 k++;
             }
         }
         k += dst_stride - width;
         src += stride;
     }
 }

 /* Write data to a plane with left prediction */
 static void left_predict(uint8_t *src, uint8_t *dst, int stride,
                          int width, int height)
 {
     int i, j;
     uint8_t prev;

     prev = 0x80; /* Set the initial value */
     for (j = 0; j < height; j++) {
         for (i = 0; i < width; i++) {
             *dst++ = src[i] - prev;
             prev   = src[i];
         }
         src += stride;
     }
 }

 /* Write data to a plane with median prediction */
 static void median_predict(UtvideoContext *c, uint8_t *src, uint8_t *dst, int stride,
                            int width, int height)
 {
     int i, j;
     int A, B;
     uint8_t prev;

     /* First line uses left neighbour prediction */
     prev = 0x80; /* Set the initial value */
     for (i = 0; i < width; i++) {
         *dst++ = src[i] - prev;
         prev   = src[i];
     }

     if (height == 1)
         return;

     src += stride;

     /*
      * Second line uses top prediction for the first sample,
      * and median for the rest.
      */
     A = B = 0;

     /* Rest of the coded part uses median prediction */
     for (j = 1; j < height; j++) {
         c->hdsp.sub_hfyu_median_pred(dst, src - stride, src, width, &A, &B);
         dst += width;
         src += stride;
     }
 }

 /* Count the usage of values in a plane */
 static void count_usage(uint8_t *src, int width,
                         int height, uint64_t *counts)
 {
     int i, j;

     for (j = 0; j < height; j++) {
         for (i = 0; i < width; i++) {
             counts[src[i]]++;
         }
         src += width;
     }
 }

 /* Calculate the actual huffman codes from the code lengths */
 static void calculate_codes(HuffEntry *he)
 {
     int last, i;
     uint32_t code;

     qsort(he, 256, sizeof(*he), ff_ut_huff_cmp_len);

     last = 255;
     while (he[last].len == 255 && last)
         last--;

     code = 1;
     for (i = last; i >= 0; i--) {
         he[i].code  = code >> (32 - he[i].len);
         code       += 0x80000000u >> (he[i].len - 1);
     }

     qsort(he, 256, sizeof(*he), huff_cmp_sym);
 }

 /* Write huffman bit codes to a memory block */
 static int write_huff_codes(uint8_t *src, uint8_t *dst, int dst_size,
                             int width, int height, HuffEntry *he)
 {
     PutBitContext pb;
     int i, j;
     int count;

     init_put_bits(&pb, dst, dst_size);

     /* Write the codes */
     for (j = 0; j < height; j++) {
         for (i = 0; i < width; i++)
             put_bits(&pb, he[src[i]].len, he[src[i]].code);

         src += width;
     }

     /* Pad output to a 32bit boundary */
     count = put_bits_count(&pb) & 0x1F;

     if (count)
         put_bits(&pb, 32 - count, 0);

     /* Get the amount of bits written */
     count = put_bits_count(&pb);

     /* Flush the rest with zeroes */
     flush_put_bits(&pb);

     return count;
 }

 static int encode_plane(AVCodecContext *avctx, uint8_t *src,
                         uint8_t *dst, int stride, int plane_no,
                         int width, int height, PutByteContext *pb)
 {
     UtvideoContext *c        = avctx->priv_data;
     uint8_t  lengths[256];
     uint64_t counts[256]     = { 0 };

     HuffEntry he[256];

     uint32_t offset = 0, slice_len = 0;
     const int cmask = ~(!plane_no && avctx->pix_fmt == AV_PIX_FMT_YUV420P);
     int      i, sstart, send = 0;
     int      symbol;
     int      ret;

     /* Do prediction / make planes */
     switch (c->frame_pred) {
     case PRED_NONE:
         for (i = 0; i < c->slices; i++) {
             sstart = send;
             send   = height * (i + 1) / c->slices & cmask;
             av_image_copy_plane(dst + sstart * width, width,
                                 src + sstart * stride, stride,
                                 width, send - sstart);
         }
         break;
     case PRED_LEFT:
         for (i = 0; i < c->slices; i++) {
             sstart = send;
             send   = height * (i + 1) / c->slices & cmask;
             left_predict(src + sstart * stride, dst + sstart * width,
                          stride, width, send - sstart);
         }
         break;
     case PRED_MEDIAN:
         for (i = 0; i < c->slices; i++) {
             sstart = send;
             send   = height * (i + 1) / c->slices & cmask;
             median_predict(c, src + sstart * stride, dst + sstart * width,
                            stride, width, send - sstart);
         }
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unknown prediction mode: %d\n",
                c->frame_pred);
         return AVERROR_OPTION_NOT_FOUND;
     }

     /* Count the usage of values */
     count_usage(dst, width, height, counts);

     /* Check for a special case where only one symbol was used */
     for (symbol = 0; symbol < 256; symbol++) {
         /* If non-zero count is found, see if it matches width * height */
         if (counts[symbol]) {
             /* Special case if only one symbol was used */
             if (counts[symbol] == width * (int64_t)height) {
                 /*
                  * Write a zero for the single symbol
                  * used in the plane, else 0xFF.
                  */
                 for (i = 0; i < 256; i++) {
                     if (i == symbol)
                         bytestream2_put_byte(pb, 0);
                     else
                         bytestream2_put_byte(pb, 0xFF);
                 }

                 /* Write zeroes for lengths */
                 for (i = 0; i < c->slices; i++)
                     bytestream2_put_le32(pb, 0);

                 /* And that's all for that plane folks */
                 return 0;
             }
             break;
         }
     }

     /* Calculate huffman lengths */
     if ((ret = ff_huff_gen_len_table(lengths, counts, 256, 1)) < 0)
         return ret;

     /*
      * Write the plane's header into the output packet:
      * - huffman code lengths (256 bytes)
      * - slice end offsets (gotten from the slice lengths)
      */
     for (i = 0; i < 256; i++) {
         bytestream2_put_byte(pb, lengths[i]);

         he[i].len = lengths[i];
         he[i].sym = i;
     }

     /* Calculate the huffman codes themselves */
     calculate_codes(he);

     send = 0;
     for (i = 0; i < c->slices; i++) {
         sstart  = send;
         send    = height * (i + 1) / c->slices & cmask;

         /*
          * Write the huffman codes to a buffer,
          * get the offset in bits and convert to bytes.
          */
         offset += write_huff_codes(dst + sstart * width, c->slice_bits,
                                    width * height + 4, width,
                                    send - sstart, he) >> 3;

         slice_len = offset - slice_len;

         /* Byteswap the written huffman codes */
         c->bdsp.bswap_buf((uint32_t *) c->slice_bits,
                           (uint32_t *) c->slice_bits,
                           slice_len >> 2);

         /* Write the offset to the stream */
         bytestream2_put_le32(pb, offset);

         /* Seek to the data part of the packet */
         bytestream2_seek_p(pb, 4 * (c->slices - i - 1) +
                            offset - slice_len, SEEK_CUR);

         /* Write the slices' data into the output packet */
         bytestream2_put_buffer(pb, c->slice_bits, slice_len);

         /* Seek back to the slice offsets */
         bytestream2_seek_p(pb, -4 * (c->slices - i - 1) - offset,
                            SEEK_CUR);

         slice_len = offset;
     }

     /* And at the end seek to the end of written slice(s) */
     bytestream2_seek_p(pb, offset, SEEK_CUR);

     return 0;
 }

 static int utvideo_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                                 const AVFrame *pic, int *got_packet)
 {
     UtvideoContext *c = avctx->priv_data;
     PutByteContext pb;

     uint32_t frame_info;

     uint8_t *dst;

     int width = avctx->width, height = avctx->height;
     int i, ret = 0;

     /* Allocate a new packet if needed, and set it to the pointer dst */
     ret = ff_alloc_packet2(avctx, pkt, (256 + 4 * c->slices + width * height) *
                            c->planes + 4, 0);

     if (ret < 0)
         return ret;

     dst = pkt->data;

     bytestream2_init_writer(&pb, dst, pkt->size);

     av_fast_padded_malloc(&c->slice_bits, &c->slice_bits_size, width * height + 4);

     if (!c->slice_bits) {
         av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer 2.\n");
         return AVERROR(ENOMEM);
     }

     /* In case of RGB, mangle the planes to Ut Video's format */
     if (avctx->pix_fmt == AV_PIX_FMT_RGBA || avctx->pix_fmt == AV_PIX_FMT_RGB24)
         mangle_rgb_planes(c->slice_buffer, c->slice_stride, pic->data[0],
                           c->planes, pic->linesize[0], width, height);

     /* Deal with the planes */
     switch (avctx->pix_fmt) {
     case AV_PIX_FMT_RGB24:
     case AV_PIX_FMT_RGBA:
         for (i = 0; i < c->planes; i++) {
             ret = encode_plane(avctx, c->slice_buffer[i] + 2 * c->slice_stride,
                                c->slice_buffer[i], c->slice_stride, i,
                                width, height, &pb);

             if (ret) {
                 av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
                 return ret;
             }
         }
         break;
     case AV_PIX_FMT_YUV422P:
         for (i = 0; i < c->planes; i++) {
             ret = encode_plane(avctx, pic->data[i], c->slice_buffer[0],
                                pic->linesize[i], i, width >> !!i, height, &pb);

             if (ret) {
                 av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
                 return ret;
             }
         }
         break;
     case AV_PIX_FMT_YUV420P:
         for (i = 0; i < c->planes; i++) {
             ret = encode_plane(avctx, pic->data[i], c->slice_buffer[0],
                                pic->linesize[i], i, width >> !!i, height >> !!i,
                                &pb);

             if (ret) {
                 av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
                 return ret;
             }
         }
         break;
     default:
         av_log(avctx, AV_LOG_ERROR, "Unknown pixel format: %d\n",
                avctx->pix_fmt);
         return AVERROR_INVALIDDATA;
     }

     /*
      * Write frame information (LE 32bit unsigned)
      * into the output packet.
      * Contains the prediction method.
      */
     frame_info = c->frame_pred << 8;
     bytestream2_put_le32(&pb, frame_info);

     /*
      * At least currently Ut Video is IDR only.
      * Set flags accordingly.
      */
 #if FF_API_CODED_FRAME
 FF_DISABLE_DEPRECATION_WARNINGS
     avctx->coded_frame->key_frame = 1;
     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

     pkt->size   = bytestream2_tell_p(&pb);
     pkt->flags |= AV_PKT_FLAG_KEY;

     /* Packet should be done */
     *got_packet = 1;

     return 0;
 }

 #define OFFSET(x) offsetof(UtvideoContext, x)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
 { "pred", "Prediction method", OFFSET(frame_pred), AV_OPT_TYPE_INT, { .i64 = PRED_LEFT }, PRED_NONE, PRED_MEDIAN, VE, "pred" },
     { "none",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_NONE }, INT_MIN, INT_MAX, VE, "pred" },
     { "left",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_LEFT }, INT_MIN, INT_MAX, VE, "pred" },
     { "gradient", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_GRADIENT }, INT_MIN, INT_MAX, VE, "pred" },
     { "median",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_MEDIAN }, INT_MIN, INT_MAX, VE, "pred" },

     { NULL},
 };

 static const AVClass utvideo_class = {
     .class_name = "utvideo",
     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,
 };

 AVCodec ff_utvideo_encoder = {
     .name           = "utvideo",
     .long_name      = NULL_IF_CONFIG_SMALL("Ut Video"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_UTVIDEO,
     .priv_data_size = sizeof(UtvideoContext),
     .priv_class     = &utvideo_class,
     .init           = utvideo_encode_init,
     .encode2        = utvideo_encode_frame,
     .close          = utvideo_encode_close,
     .capabilities   = AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_INTRA_ONLY,
     .pix_fmts       = (const enum AVPixelFormat[]) {
                           AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA, AV_PIX_FMT_YUV422P,
                           AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE
                       },
 };
	/*
	* Ut Video encoder
	* Copyright (c) 2012 Jan Ekström
	*
	* 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
	* Ut Video encoder
	*/

	#include "libavutil/imgutils.h"
	#include "libavutil/intreadwrite.h"
	#include "libavutil/opt.h"

	#include "avcodec.h"
	#include "internal.h"
	#include "bswapdsp.h"
	#include "bytestream.h"
	#include "put_bits.h"
	#include "huffyuvencdsp.h"
	#include "mathops.h"
	#include "utvideo.h"
	#include "huffman.h"

	/* Compare huffentry symbols */
	static int huff_cmp_sym(const void a, const void b)
	{
	const HuffEntry aa = a, bb = b;
	return aa->sym - bb->sym;
	}

	static av_cold int utvideo_encode_close(AVCodecContext *avctx)
	{
	UtvideoContext *c = avctx->priv_data;
	int i;

	av_freep(&c->slice_bits);
	for (i = 0; i < 4; i++)
	av_freep(&c->slice_buffer[i]);

	return 0;
	}

	static av_cold int utvideo_encode_init(AVCodecContext *avctx)
	{
	UtvideoContext *c = avctx->priv_data;
	int i, subsampled_height;
	uint32_t original_format;

	c->avctx = avctx;
	c->frame_info_size = 4;
	c->slice_stride = FFALIGN(avctx->width, 32);

	switch (avctx->pix_fmt) {
	case AV_PIX_FMT_RGB24:
	c->planes = 3;
	avctx->codec_tag = MKTAG('U', 'L', 'R', 'G');
	original_format = UTVIDEO_RGB;
	break;
	case AV_PIX_FMT_RGBA:
	c->planes = 4;
	avctx->codec_tag = MKTAG('U', 'L', 'R', 'A');
	original_format = UTVIDEO_RGBA;
	break;
	case AV_PIX_FMT_YUV420P:
	if (avctx->width & 1 \|\| avctx->height & 1) {
	av_log(avctx, AV_LOG_ERROR,
	"4:2:0 video requires even width and height.\n");
	return AVERROR_INVALIDDATA;
	}
	c->planes = 3;
	if (avctx->colorspace == AVCOL_SPC_BT709)
	avctx->codec_tag = MKTAG('U', 'L', 'H', '0');
	else
	avctx->codec_tag = MKTAG('U', 'L', 'Y', '0');
	original_format = UTVIDEO_420;
	break;
	case AV_PIX_FMT_YUV422P:
	if (avctx->width & 1) {
	av_log(avctx, AV_LOG_ERROR,
	"4:2:2 video requires even width.\n");
	return AVERROR_INVALIDDATA;
	}
	c->planes = 3;
	if (avctx->colorspace == AVCOL_SPC_BT709)
	avctx->codec_tag = MKTAG('U', 'L', 'H', '2');
	else
	avctx->codec_tag = MKTAG('U', 'L', 'Y', '2');
	original_format = UTVIDEO_422;
	break;
	default:
	av_log(avctx, AV_LOG_ERROR, "Unknown pixel format: %d\n",
	avctx->pix_fmt);
	return AVERROR_INVALIDDATA;
	}

	ff_bswapdsp_init(&c->bdsp);
	ff_huffyuvencdsp_init(&c->hdsp);

	#if FF_API_PRIVATE_OPT
	FF_DISABLE_DEPRECATION_WARNINGS
	/* Check the prediction method, and error out if unsupported */
	if (avctx->prediction_method < 0 \|\| avctx->prediction_method > 4) {
	av_log(avctx, AV_LOG_WARNING,
	"Prediction method %d is not supported in Ut Video.\n",
	avctx->prediction_method);
	return AVERROR_OPTION_NOT_FOUND;
	}

	if (avctx->prediction_method == FF_PRED_PLANE) {
	av_log(avctx, AV_LOG_ERROR,
	"Plane prediction is not supported in Ut Video.\n");
	return AVERROR_OPTION_NOT_FOUND;
	}

	/* Convert from libavcodec prediction type to Ut Video's */
	if (avctx->prediction_method)
	c->frame_pred = ff_ut_pred_order[avctx->prediction_method];
	FF_ENABLE_DEPRECATION_WARNINGS
	#endif

	if (c->frame_pred == PRED_GRADIENT) {
	av_log(avctx, AV_LOG_ERROR, "Gradient prediction is not supported.\n");
	return AVERROR_OPTION_NOT_FOUND;
	}

	/*
	* Check the asked slice count for obviously invalid
	* values (> 256 or negative).
	*/
	if (avctx->slices > 256 \|\| avctx->slices < 0) {
	av_log(avctx, AV_LOG_ERROR,
	"Slice count %d is not supported in Ut Video (theoretical range is 0-256).\n",
	avctx->slices);
	return AVERROR(EINVAL);
	}

	/* Check that the slice count is not larger than the subsampled height */
	subsampled_height = avctx->height >> av_pix_fmt_desc_get(avctx->pix_fmt)->log2_chroma_h;
	if (avctx->slices > subsampled_height) {
	av_log(avctx, AV_LOG_ERROR,
	"Slice count %d is larger than the subsampling-applied height %d.\n",
	avctx->slices, subsampled_height);
	return AVERROR(EINVAL);
	}

	/* extradata size is 4 * 32bit */
	avctx->extradata_size = 16;

	avctx->extradata = av_mallocz(avctx->extradata_size +
	AV_INPUT_BUFFER_PADDING_SIZE);

	if (!avctx->extradata) {
	av_log(avctx, AV_LOG_ERROR, "Could not allocate extradata.\n");
	utvideo_encode_close(avctx);
	return AVERROR(ENOMEM);
	}

	for (i = 0; i < c->planes; i++) {
	c->slice_buffer[i] = av_malloc(c->slice_stride * (avctx->height + 2) +
	AV_INPUT_BUFFER_PADDING_SIZE);
	if (!c->slice_buffer[i]) {
	av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer 1.\n");
	utvideo_encode_close(avctx);
	return AVERROR(ENOMEM);
	}
	}

	/*
	* Set the version of the encoder.
	* Last byte is "implementation ID", which is
	* obtained from the creator of the format.
	* Libavcodec has been assigned with the ID 0xF0.
	*/
	AV_WB32(avctx->extradata, MKTAG(1, 0, 0, 0xF0));

	/*
	* Set the "original format"
	* Not used for anything during decoding.
	*/
	AV_WL32(avctx->extradata + 4, original_format);

	/* Write 4 as the 'frame info size' */
	AV_WL32(avctx->extradata + 8, c->frame_info_size);

	/*
	* Set how many slices are going to be used.
	* By default uses multiple slices depending on the subsampled height.
	* This enables multithreading in the official decoder.
	*/
	if (!avctx->slices) {
	c->slices = subsampled_height / 120;

	if (!c->slices)
	c->slices = 1;
	else if (c->slices > 256)
	c->slices = 256;
	} else {
	c->slices = avctx->slices;
	}

	/* Set compression mode */
	c->compression = COMP_HUFF;

	/*
	* Set the encoding flags:
	* - Slice count minus 1
	* - Interlaced encoding mode flag, set to zero for now.
	* - Compression mode (none/huff)
	* And write the flags.
	*/
	c->flags = (c->slices - 1) << 24;
	c->flags \|= 0 << 11; // bit field to signal interlaced encoding mode
	c->flags \|= c->compression;

	AV_WL32(avctx->extradata + 12, c->flags);

	return 0;
	}

	static void mangle_rgb_planes(uint8_t dst[4], int dst_stride, uint8_t src,
	int step, int stride, int width, int height)
	{
	int i, j;
	int k = 2 * dst_stride;
	unsigned int g;

	for (j = 0; j < height; j++) {
	if (step == 3) {
	for (i = 0; i < width * step; i += step) {
	g = src[i + 1];
	dst[0][k] = g;
	g += 0x80;
	dst[1][k] = src[i + 2] - g;
	dst[2][k] = src[i + 0] - g;
	k++;
	}
	} else {
	for (i = 0; i < width * step; i += step) {
	g = src[i + 1];
	dst[0][k] = g;
	g += 0x80;
	dst[1][k] = src[i + 2] - g;
	dst[2][k] = src[i + 0] - g;
	dst[3][k] = src[i + 3];
	k++;
	}
	}
	k += dst_stride - width;
	src += stride;
	}
	}

	/* Write data to a plane with left prediction */
	static void left_predict(uint8_t src, uint8_t dst, int stride,
	int width, int height)
	{
	int i, j;
	uint8_t prev;

	prev = 0x80; /* Set the initial value */
	for (j = 0; j < height; j++) {
	for (i = 0; i < width; i++) {
	*dst++ = src[i] - prev;
	prev = src[i];
	}
	src += stride;
	}
	}

	/* Write data to a plane with median prediction */
	static void median_predict(UtvideoContext c, uint8_t src, uint8_t *dst, int stride,
	int width, int height)
	{
	int i, j;
	int A, B;
	uint8_t prev;

	/* First line uses left neighbour prediction */
	prev = 0x80; /* Set the initial value */
	for (i = 0; i < width; i++) {
	*dst++ = src[i] - prev;
	prev = src[i];
	}

	if (height == 1)
	return;

	src += stride;

	/*
	* Second line uses top prediction for the first sample,
	* and median for the rest.
	*/
	A = B = 0;

	/* Rest of the coded part uses median prediction */
	for (j = 1; j < height; j++) {
	c->hdsp.sub_hfyu_median_pred(dst, src - stride, src, width, &A, &B);
	dst += width;
	src += stride;
	}
	}

	/* Count the usage of values in a plane */
	static void count_usage(uint8_t *src, int width,
	int height, uint64_t *counts)
	{
	int i, j;

	for (j = 0; j < height; j++) {
	for (i = 0; i < width; i++) {
	counts[src[i]]++;
	}
	src += width;
	}
	}

	/* Calculate the actual huffman codes from the code lengths */
	static void calculate_codes(HuffEntry *he)
	{
	int last, i;
	uint32_t code;

	qsort(he, 256, sizeof(*he), ff_ut_huff_cmp_len);

	last = 255;
	while (he[last].len == 255 && last)
	last--;

	code = 1;
	for (i = last; i >= 0; i--) {
	he[i].code = code >> (32 - he[i].len);
	code += 0x80000000u >> (he[i].len - 1);
	}

	qsort(he, 256, sizeof(*he), huff_cmp_sym);
	}

	/* Write huffman bit codes to a memory block */
	static int write_huff_codes(uint8_t src, uint8_t dst, int dst_size,
	int width, int height, HuffEntry *he)
	{
	PutBitContext pb;
	int i, j;
	int count;

	init_put_bits(&pb, dst, dst_size);

	/* Write the codes */
	for (j = 0; j < height; j++) {
	for (i = 0; i < width; i++)
	put_bits(&pb, he[src[i]].len, he[src[i]].code);

	src += width;
	}

	/* Pad output to a 32bit boundary */
	count = put_bits_count(&pb) & 0x1F;

	if (count)
	put_bits(&pb, 32 - count, 0);

	/* Get the amount of bits written */
	count = put_bits_count(&pb);

	/* Flush the rest with zeroes */
	flush_put_bits(&pb);

	return count;
	}

	static int encode_plane(AVCodecContext avctx, uint8_t src,
	uint8_t *dst, int stride, int plane_no,
	int width, int height, PutByteContext *pb)
	{
	UtvideoContext *c = avctx->priv_data;
	uint8_t lengths[256];
	uint64_t counts[256] = { 0 };

	HuffEntry he[256];

	uint32_t offset = 0, slice_len = 0;
	const int cmask = ~(!plane_no && avctx->pix_fmt == AV_PIX_FMT_YUV420P);
	int i, sstart, send = 0;
	int symbol;
	int ret;

	/* Do prediction / make planes */
	switch (c->frame_pred) {
	case PRED_NONE:
	for (i = 0; i < c->slices; i++) {
	sstart = send;
	send = height * (i + 1) / c->slices & cmask;
	av_image_copy_plane(dst + sstart * width, width,
	src + sstart * stride, stride,
	width, send - sstart);
	}
	break;
	case PRED_LEFT:
	for (i = 0; i < c->slices; i++) {
	sstart = send;
	send = height * (i + 1) / c->slices & cmask;
	left_predict(src + sstart * stride, dst + sstart * width,
	stride, width, send - sstart);
	}
	break;
	case PRED_MEDIAN:
	for (i = 0; i < c->slices; i++) {
	sstart = send;
	send = height * (i + 1) / c->slices & cmask;
	median_predict(c, src + sstart * stride, dst + sstart * width,
	stride, width, send - sstart);
	}
	break;
	default:
	av_log(avctx, AV_LOG_ERROR, "Unknown prediction mode: %d\n",
	c->frame_pred);
	return AVERROR_OPTION_NOT_FOUND;
	}

	/* Count the usage of values */
	count_usage(dst, width, height, counts);

	/* Check for a special case where only one symbol was used */
	for (symbol = 0; symbol < 256; symbol++) {
	/* If non-zero count is found, see if it matches width * height */
	if (counts[symbol]) {
	/* Special case if only one symbol was used */
	if (counts[symbol] == width * (int64_t)height) {
	/*
	* Write a zero for the single symbol
	* used in the plane, else 0xFF.
	*/
	for (i = 0; i < 256; i++) {
	if (i == symbol)
	bytestream2_put_byte(pb, 0);
	else
	bytestream2_put_byte(pb, 0xFF);
	}

	/* Write zeroes for lengths */
	for (i = 0; i < c->slices; i++)
	bytestream2_put_le32(pb, 0);

	/* And that's all for that plane folks */
	return 0;
	}
	break;
	}
	}

	/* Calculate huffman lengths */
	if ((ret = ff_huff_gen_len_table(lengths, counts, 256, 1)) < 0)
	return ret;

	/*
	* Write the plane's header into the output packet:
	* - huffman code lengths (256 bytes)
	* - slice end offsets (gotten from the slice lengths)
	*/
	for (i = 0; i < 256; i++) {
	bytestream2_put_byte(pb, lengths[i]);

	he[i].len = lengths[i];
	he[i].sym = i;
	}

	/* Calculate the huffman codes themselves */
	calculate_codes(he);

	send = 0;
	for (i = 0; i < c->slices; i++) {
	sstart = send;
	send = height * (i + 1) / c->slices & cmask;

	/*
	* Write the huffman codes to a buffer,
	* get the offset in bits and convert to bytes.
	*/
	offset += write_huff_codes(dst + sstart * width, c->slice_bits,
	width * height + 4, width,
	send - sstart, he) >> 3;

	slice_len = offset - slice_len;

	/* Byteswap the written huffman codes */
	c->bdsp.bswap_buf((uint32_t *) c->slice_bits,
	(uint32_t *) c->slice_bits,
	slice_len >> 2);

	/* Write the offset to the stream */
	bytestream2_put_le32(pb, offset);

	/* Seek to the data part of the packet */
	bytestream2_seek_p(pb, 4 * (c->slices - i - 1) +
	offset - slice_len, SEEK_CUR);

	/* Write the slices' data into the output packet */
	bytestream2_put_buffer(pb, c->slice_bits, slice_len);

	/* Seek back to the slice offsets */
	bytestream2_seek_p(pb, -4 * (c->slices - i - 1) - offset,
	SEEK_CUR);

	slice_len = offset;
	}

	/* And at the end seek to the end of written slice(s) */
	bytestream2_seek_p(pb, offset, SEEK_CUR);

	return 0;
	}

	static int utvideo_encode_frame(AVCodecContext avctx, AVPacket pkt,
	const AVFrame pic, int got_packet)
	{
	UtvideoContext *c = avctx->priv_data;
	PutByteContext pb;

	uint32_t frame_info;

	uint8_t *dst;

	int width = avctx->width, height = avctx->height;
	int i, ret = 0;

	/* Allocate a new packet if needed, and set it to the pointer dst */
	ret = ff_alloc_packet2(avctx, pkt, (256 + 4 * c->slices + width * height) *
	c->planes + 4, 0);

	if (ret < 0)
	return ret;

	dst = pkt->data;

	bytestream2_init_writer(&pb, dst, pkt->size);

	av_fast_padded_malloc(&c->slice_bits, &c->slice_bits_size, width * height + 4);

	if (!c->slice_bits) {
	av_log(avctx, AV_LOG_ERROR, "Cannot allocate temporary buffer 2.\n");
	return AVERROR(ENOMEM);
	}

	/* In case of RGB, mangle the planes to Ut Video's format */
	if (avctx->pix_fmt == AV_PIX_FMT_RGBA \|\| avctx->pix_fmt == AV_PIX_FMT_RGB24)
	mangle_rgb_planes(c->slice_buffer, c->slice_stride, pic->data[0],
	c->planes, pic->linesize[0], width, height);

	/* Deal with the planes */
	switch (avctx->pix_fmt) {
	case AV_PIX_FMT_RGB24:
	case AV_PIX_FMT_RGBA:
	for (i = 0; i < c->planes; i++) {
	ret = encode_plane(avctx, c->slice_buffer[i] + 2 * c->slice_stride,
	c->slice_buffer[i], c->slice_stride, i,
	width, height, &pb);

	if (ret) {
	av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
	return ret;
	}
	}
	break;
	case AV_PIX_FMT_YUV422P:
	for (i = 0; i < c->planes; i++) {
	ret = encode_plane(avctx, pic->data[i], c->slice_buffer[0],
	pic->linesize[i], i, width >> !!i, height, &pb);

	if (ret) {
	av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
	return ret;
	}
	}
	break;
	case AV_PIX_FMT_YUV420P:
	for (i = 0; i < c->planes; i++) {
	ret = encode_plane(avctx, pic->data[i], c->slice_buffer[0],
	pic->linesize[i], i, width >> !!i, height >> !!i,
	&pb);

	if (ret) {
	av_log(avctx, AV_LOG_ERROR, "Error encoding plane %d.\n", i);
	return ret;
	}
	}
	break;
	default:
	av_log(avctx, AV_LOG_ERROR, "Unknown pixel format: %d\n",
	avctx->pix_fmt);
	return AVERROR_INVALIDDATA;
	}

	/*
	* Write frame information (LE 32bit unsigned)
	* into the output packet.
	* Contains the prediction method.
	*/
	frame_info = c->frame_pred << 8;
	bytestream2_put_le32(&pb, frame_info);

	/*
	* At least currently Ut Video is IDR only.
	* Set flags accordingly.
	*/
	#if FF_API_CODED_FRAME
	FF_DISABLE_DEPRECATION_WARNINGS
	avctx->coded_frame->key_frame = 1;
	avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
	FF_ENABLE_DEPRECATION_WARNINGS
	#endif

	pkt->size = bytestream2_tell_p(&pb);
	pkt->flags \|= AV_PKT_FLAG_KEY;

	/* Packet should be done */
	*got_packet = 1;

	return 0;
	}

	#define OFFSET(x) offsetof(UtvideoContext, x)
	#define VE AV_OPT_FLAG_VIDEO_PARAM \| AV_OPT_FLAG_ENCODING_PARAM
	static const AVOption options[] = {
	{ "pred", "Prediction method", OFFSET(frame_pred), AV_OPT_TYPE_INT, { .i64 = PRED_LEFT }, PRED_NONE, PRED_MEDIAN, VE, "pred" },
	{ "none", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_NONE }, INT_MIN, INT_MAX, VE, "pred" },
	{ "left", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_LEFT }, INT_MIN, INT_MAX, VE, "pred" },
	{ "gradient", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_GRADIENT }, INT_MIN, INT_MAX, VE, "pred" },
	{ "median", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PRED_MEDIAN }, INT_MIN, INT_MAX, VE, "pred" },

	{ NULL},
	};

	static const AVClass utvideo_class = {
	.class_name = "utvideo",
	.item_name = av_default_item_name,
	.option = options,
	.version = LIBAVUTIL_VERSION_INT,
	};

	AVCodec ff_utvideo_encoder = {
	.name = "utvideo",
	.long_name = NULL_IF_CONFIG_SMALL("Ut Video"),
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_UTVIDEO,
	.priv_data_size = sizeof(UtvideoContext),
	.priv_class = &utvideo_class,
	.init = utvideo_encode_init,
	.encode2 = utvideo_encode_frame,
	.close = utvideo_encode_close,
	.capabilities = AV_CODEC_CAP_FRAME_THREADS \| AV_CODEC_CAP_INTRA_ONLY,
	.pix_fmts = (const enum AVPixelFormat[]) {
	AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA, AV_PIX_FMT_YUV422P,
	AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE
	},
	};