text: /*
   * NuppelVideo decoder
   * Copyright (c) 2006 Reimar Doeffinger
   *
   * 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 <stdio.h>
  #include <stdlib.h>
  #include <limits.h>
  
  #include "libavutil/bswap.h"
  #include "libavutil/common.h"
  #include "libavutil/lzo.h"
  #include "libavutil/imgutils.h"
  #include "avcodec.h"
  #include "internal.h"
  #include "rtjpeg.h"
  
  typedef struct {
      AVFrame *pic;
      int codec_frameheader;
      int quality;
      int width, height;
      unsigned int decomp_size;
      unsigned char *decomp_buf;
      uint32_t lq[64], cq[64];
      RTJpegContext rtj;
      DSPContext dsp;
  } NuvContext;
  
  static const uint8_t fallback_lquant[] = {
      16,  11,  10,  16,  24,  40,  51,  61,
      12,  12,  14,  19,  26,  58,  60,  55,
      14,  13,  16,  24,  40,  57,  69,  56,
      14,  17,  22,  29,  51,  87,  80,  62,
      18,  22,  37,  56,  68, 109, 103,  77,
      24,  35,  55,  64,  81, 104, 113,  92,
      49,  64,  78,  87, 103, 121, 120, 101,
      72,  92,  95,  98, 112, 100, 103,  99
  };
  
  static const uint8_t fallback_cquant[] = {
      17, 18, 24, 47, 99, 99, 99, 99,
      18, 21, 26, 66, 99, 99, 99, 99,
      24, 26, 56, 99, 99, 99, 99, 99,
      47, 66, 99, 99, 99, 99, 99, 99,
      99, 99, 99, 99, 99, 99, 99, 99,
      99, 99, 99, 99, 99, 99, 99, 99,
      99, 99, 99, 99, 99, 99, 99, 99,
      99, 99, 99, 99, 99, 99, 99, 99
  };
  
  /**
   * @brief copy frame data from buffer to AVFrame, handling stride.
   * @param f destination AVFrame
   * @param src source buffer, does not use any line-stride
   * @param width width of the video frame
   * @param height height of the video frame
   */
  static void copy_frame(AVFrame *f, const uint8_t *src, int width, int height)
  {
      AVPicture pic;
      avpicture_fill(&pic, src, AV_PIX_FMT_YUV420P, width, height);
      av_picture_copy((AVPicture *)f, &pic, AV_PIX_FMT_YUV420P, width, height);
  }
  
  /**
   * @brief extract quantization tables from codec data into our context
   */
  static int get_quant(AVCodecContext *avctx, NuvContext *c, const uint8_t *buf,
                       int size)
  {
      int i;
      if (size < 2 * 64 * 4) {
          av_log(avctx, AV_LOG_ERROR, "insufficient rtjpeg quant data\n");
          return AVERROR_INVALIDDATA;
      }
      for (i = 0; i < 64; i++, buf += 4)
          c->lq[i] = AV_RL32(buf);
      for (i = 0; i < 64; i++, buf += 4)
          c->cq[i] = AV_RL32(buf);
      return 0;
  }
  
  /**
   * @brief set quantization tables from a quality value
   */
  static void get_quant_quality(NuvContext *c, int quality)
  {
      int i;
      quality = FFMAX(quality, 1);
      for (i = 0; i < 64; i++) {
          c->lq[i] = (fallback_lquant[i] << 7) / quality;
          c->cq[i] = (fallback_cquant[i] << 7) / quality;
      }
  }
  
  static int codec_reinit(AVCodecContext *avctx, int width, int height,
                          int quality)
  {
      NuvContext *c = avctx->priv_data;
      int ret;
  
      width  = FFALIGN(width,  2);
      height = FFALIGN(height, 2);
      if (quality >= 0)
          get_quant_quality(c, quality);
      if (width != c->width || height != c->height) {
          // also reserve space for a possible additional header
          int buf_size = height * width * 3 / 2
                       + FFMAX(AV_LZO_OUTPUT_PADDING, FF_INPUT_BUFFER_PADDING_SIZE)
                       + RTJPEG_HEADER_SIZE;
          if (buf_size > INT_MAX/8)
              return -1;
          if ((ret = av_image_check_size(height, width, 0, avctx)) < 0)
              return ret;
          avctx->width  = c->width  = width;
          avctx->height = c->height = height;
          av_fast_malloc(&c->decomp_buf, &c->decomp_size,
                         buf_size);
          if (!c->decomp_buf) {
              av_log(avctx, AV_LOG_ERROR,
                     "Can't allocate decompression buffer.\n");
              return AVERROR(ENOMEM);
          }
          ff_rtjpeg_decode_init(&c->rtj, &c->dsp, c->width, c->height,
                                c->lq, c->cq);
          av_frame_unref(c->pic);
          return 1;
      } else if (quality != c->quality)
          ff_rtjpeg_decode_init(&c->rtj, &c->dsp, c->width, c->height,
                                c->lq, c->cq);
  
      return 0;
  }
  
  static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                          AVPacket *avpkt)
  {
      const uint8_t *buf = avpkt->data;
      int buf_size       = avpkt->size;
      NuvContext *c      = avctx->priv_data;
      AVFrame *picture   = data;
      int orig_size      = buf_size;
      int keyframe, ret;
      int size_change = 0;
      int result, init_frame = !avctx->frame_number;
      enum {
          NUV_UNCOMPRESSED  = '0',
          NUV_RTJPEG        = '1',
          NUV_RTJPEG_IN_LZO = '2',
          NUV_LZO           = '3',
          NUV_BLACK         = 'N',
          NUV_COPY_LAST     = 'L'
      } comptype;
  
      if (buf_size < 12) {
          av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
          return AVERROR_INVALIDDATA;
      }
  
      // codec data (rtjpeg quant tables)
      if (buf[0] == 'D' && buf[1] == 'R') {
          int ret;
          // skip rest of the frameheader.
          buf       = &buf[12];
          buf_size -= 12;
          ret       = get_quant(avctx, c, buf, buf_size);
          if (ret < 0)
              return ret;
          ff_rtjpeg_decode_init(&c->rtj, &c->dsp, c->width, c->height, c->lq,
                                c->cq);
          return orig_size;
      }
  
      if (buf_size < 12 || buf[0] != 'V') {
          av_log(avctx, AV_LOG_ERROR, "not a nuv video frame\n");
          return AVERROR_INVALIDDATA;
      }
      comptype = buf[1];
      switch (comptype) {
      case NUV_RTJPEG_IN_LZO:
      case NUV_RTJPEG:
          keyframe = !buf[2];
          break;
      case NUV_COPY_LAST:
          keyframe = 0;
          break;
      default:
          keyframe = 1;
          break;
      }
  retry:
      // skip rest of the frameheader.
      buf       = &buf[12];
      buf_size -= 12;
      if (comptype == NUV_RTJPEG_IN_LZO || comptype == NUV_LZO) {
          int outlen = c->decomp_size - FFMAX(FF_INPUT_BUFFER_PADDING_SIZE, AV_LZO_OUTPUT_PADDING);
          int inlen  = buf_size;
          if (av_lzo1x_decode(c->decomp_buf, &outlen, buf, &inlen)) {
              av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
              return AVERROR_INVALIDDATA;
          }
          buf      = c->decomp_buf;
          buf_size = c->decomp_size - FFMAX(FF_INPUT_BUFFER_PADDING_SIZE, AV_LZO_OUTPUT_PADDING) - outlen;
          memset(c->decomp_buf + buf_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
      }
      if (c->codec_frameheader) {
          int w, h, q;
          if (buf_size < RTJPEG_HEADER_SIZE) {
              av_log(avctx, AV_LOG_ERROR, "Too small NUV video frame\n");
              return AVERROR_INVALIDDATA;
          }
          // There seem to exist two variants of this header: one starts with 'V'
          // and 5 bytes unknown, the other matches current MythTV and is 4 bytes size,
          // 1 byte header size (== 12), 1 byte version (== 0)
          if (buf[0] != 'V' && AV_RL16(&buf[4]) != 0x000c) {
              av_log(avctx, AV_LOG_ERROR, "Unknown secondary frame header (wrong codec_tag?)\n");
              return AVERROR_INVALIDDATA;
          }
          w = AV_RL16(&buf[6]);
          h = AV_RL16(&buf[8]);
          q = buf[10];
          if ((result = codec_reinit(avctx, w, h, q)) < 0)
              return result;
          if (result) {
              buf = avpkt->data;
              buf_size = avpkt->size;
              size_change = 1;
              goto retry;
          }
          buf       = &buf[RTJPEG_HEADER_SIZE];
          buf_size -= RTJPEG_HEADER_SIZE;
      }
  
      if (size_change || keyframe) {
          av_frame_unref(c->pic);
          init_frame = 1;
      }
  
      if ((result = ff_reget_buffer(avctx, c->pic)) < 0)
          return result;
      if (init_frame) {
          memset(c->pic->data[0], 0,    avctx->height * c->pic->linesize[0]);
          memset(c->pic->data[1], 0x80, avctx->height * c->pic->linesize[1] / 2);
          memset(c->pic->data[2], 0x80, avctx->height * c->pic->linesize[2] / 2);
      }
  
      c->pic->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
      c->pic->key_frame = keyframe;
      // decompress/copy/whatever data
      switch (comptype) {
      case NUV_LZO:
      case NUV_UNCOMPRESSED: {
          int height = c->height;
          if (buf_size < c->width * height * 3 / 2) {
              av_log(avctx, AV_LOG_ERROR, "uncompressed frame too short\n");
              height = buf_size / c->width / 3 * 2;
          }
          if(height > 0)
              copy_frame(c->pic, buf, c->width, height);
          break;
      }
      case NUV_RTJPEG_IN_LZO:
      case NUV_RTJPEG:
          ret = ff_rtjpeg_decode_frame_yuv420(&c->rtj, c->pic, buf, buf_size);
          if (ret < 0)
              return ret;
          break;
      case NUV_BLACK:
          memset(c->pic->data[0], 0, c->width * c->height);
          memset(c->pic->data[1], 128, c->width * c->height / 4);
          memset(c->pic->data[2], 128, c->width * c->height / 4);
          break;
      case NUV_COPY_LAST:
          /* nothing more to do here */
          break;
      default:
          av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
          return AVERROR_INVALIDDATA;
      }
  
      if ((result = av_frame_ref(picture, c->pic)) < 0)
          return result;
  
      *got_frame = 1;
      return orig_size;
  }
  
  static av_cold int decode_init(AVCodecContext *avctx)
  {
      NuvContext *c  = avctx->priv_data;
      int ret;
  
      c->pic = av_frame_alloc();
      if (!c->pic)
          return AVERROR(ENOMEM);
  
      avctx->pix_fmt = AV_PIX_FMT_YUV420P;
      c->decomp_buf  = NULL;
      c->quality     = -1;
      c->width       = 0;
      c->height      = 0;
  
      c->codec_frameheader = avctx->codec_tag == MKTAG('R', 'J', 'P', 'G');
  
      if (avctx->extradata_size)
          get_quant(avctx, c, avctx->extradata, avctx->extradata_size);
  
      ff_dsputil_init(&c->dsp, avctx);
  
      if ((ret = codec_reinit(avctx, avctx->width, avctx->height, -1)) < 0)
          return ret;
  
      return 0;
  }
  
  static av_cold int decode_end(AVCodecContext *avctx)
  {
      NuvContext *c = avctx->priv_data;
  
      av_freep(&c->decomp_buf);
      av_frame_free(&c->pic);
  
      return 0;
  }
  
  AVCodec ff_nuv_decoder = {
      .name           = "nuv",
      .long_name      = NULL_IF_CONFIG_SMALL("NuppelVideo/RTJPEG"),
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_NUV,
      .priv_data_size = sizeof(NuvContext),
      .init           = decode_init,
      .close          = decode_end,
      .decode         = decode_frame,
      .capabilities   = CODEC_CAP_DR1,
  };
  