libavcodec/cljrenc.c

   1 /*
   2  * Cirrus Logic AccuPak (CLJR) encoder
   3  * Copyright (c) 2003 Alex Beregszaszi
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * Cirrus Logic AccuPak encoder.
  25  */
  26
  27 #include "libavutil/opt.h"
  28
  29 #include "avcodec.h"
  30 #include "codec_internal.h"
  31 #include "encode.h"
  32 #include "put_bits.h"
  33
  34 typedef struct CLJRContext {
  35     AVClass        *avclass;
  36     int             dither_type;
  37 } CLJRContext;
  38
  39 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
  40                         const AVFrame *p, int *got_packet)
  41 {
  42     CLJRContext *a = avctx->priv_data;
  43     PutBitContext pb;
  44     int x, y, ret;
  45     uint32_t dither= avctx->frame_number;
  46     static const uint32_t ordered_dither[2][2] =
  47     {
  48         { 0x10400000, 0x104F0000 },
  49         { 0xCB2A0000, 0xCB250000 },
  50     };
  51
  52     if (avctx->width%4 && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
  53          av_log(avctx, AV_LOG_ERROR,
  54                 "Widths which are not a multiple of 4 might fail with some decoders, "
  55                 "use vstrict=-1 / -strict -1 to use %d anyway.\n", avctx->width);
  56          return AVERROR_EXPERIMENTAL;
  57     }
  58
  59     ret = ff_get_encode_buffer(avctx, pkt, 4 * avctx->height * ((avctx->width + 3) / 4), 0);
  60     if (ret < 0)
  61         return ret;
  62
  63     init_put_bits(&pb, pkt->data, pkt->size);
  64
  65     for (y = 0; y < avctx->height; y++) {
  66         uint8_t *luma = &p->data[0][y * p->linesize[0]];
  67         uint8_t *cb   = &p->data[1][y * p->linesize[1]];
  68         uint8_t *cr   = &p->data[2][y * p->linesize[2]];
  69         uint8_t luma_tmp[4];
  70         for (x = 0; x < avctx->width; x += 4) {
  71             switch (a->dither_type) {
  72             case 0: dither = 0x492A0000;                       break;
  73             case 1: dither = dither * 1664525 + 1013904223;    break;
  74             case 2: dither = ordered_dither[ y&1 ][ (x>>2)&1 ];break;
  75             }
  76             if (x+3 >= avctx->width) {
  77                 memset(luma_tmp, 0, sizeof(luma_tmp));
  78                 memcpy(luma_tmp, luma, avctx->width - x);
  79                 luma = luma_tmp;
  80             }
  81             put_bits(&pb, 5, (249*(luma[3] +  (dither>>29)   )) >> 11);
  82             put_bits(&pb, 5, (249*(luma[2] + ((dither>>26)&7))) >> 11);
  83             put_bits(&pb, 5, (249*(luma[1] + ((dither>>23)&7))) >> 11);
  84             put_bits(&pb, 5, (249*(luma[0] + ((dither>>20)&7))) >> 11);
  85             luma += 4;
  86             put_bits(&pb, 6, (253*(*(cb++) + ((dither>>18)&3))) >> 10);
  87             put_bits(&pb, 6, (253*(*(cr++) + ((dither>>16)&3))) >> 10);
  88         }
  89     }
  90
  91     flush_put_bits(&pb);
  92
  93     *got_packet = 1;
  94     return 0;
  95 }
  96
  97 #define OFFSET(x) offsetof(CLJRContext, x)
  98 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
  99 static const AVOption options[] = {
 100     { "dither_type",   "Dither type",   OFFSET(dither_type),        AV_OPT_TYPE_INT, { .i64=1 }, 0, 2, VE},
 101     { NULL },
 102 };
 103
 104 static const AVClass cljr_class = {
 105     .class_name = "cljr encoder",
 106     .item_name  = av_default_item_name,
 107     .option     = options,
 108     .version    = LIBAVUTIL_VERSION_INT,
 109 };
 110
 111 const FFCodec ff_cljr_encoder = {
 112     .p.name         = "cljr",
 113     .p.long_name    = NULL_IF_CONFIG_SMALL("Cirrus Logic AccuPak"),
 114     .p.type         = AVMEDIA_TYPE_VIDEO,
 115     .p.id           = AV_CODEC_ID_CLJR,
 116     .p.capabilities = AV_CODEC_CAP_DR1,
 117     .priv_data_size = sizeof(CLJRContext),
 118     FF_CODEC_ENCODE_CB(encode_frame),
 119     .p.pix_fmts     = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV411P,
 120                                                    AV_PIX_FMT_NONE },
 121     .p.priv_class   = &cljr_class,
 122 };