libavcodec/bitpacked_enc.c

   1 /*
   2  * bitpacked encoder
   3  *
   4  * Copyright (c) 2021 Limin Wang
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include "avcodec.h"
  24 #include "codec_internal.h"
  25 #include "encode.h"
  26 #include "internal.h"
  27 #include "put_bits.h"
  28 #include "libavutil/pixdesc.h"
  29
  30 struct BitpackedContext {
  31     int (*encode)(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *frame);
  32 };
  33
  34 static int encode_yuv422p10(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *frame)
  35 {
  36     const int buf_size = avctx->height * avctx->width * avctx->bits_per_coded_sample / 8;
  37     int ret;
  38     uint8_t *dst;
  39     const uint16_t *y;
  40     const uint16_t *u;
  41     const uint16_t *v;
  42     PutBitContext pb;
  43
  44     ret = ff_get_encode_buffer(avctx, pkt,  buf_size, 0);
  45     if (ret < 0) {
  46         av_log(avctx, AV_LOG_ERROR, "Error getting output packet.\n");
  47         return ret;
  48     }
  49     dst = pkt->data;
  50
  51     init_put_bits(&pb, dst, buf_size);
  52
  53     for (int i = 0; i < avctx->height; i++) {
  54         y = (uint16_t*)(frame->data[0] + i * frame->linesize[0]);
  55         u = (uint16_t*)(frame->data[1] + i * frame->linesize[1]);
  56         v = (uint16_t*)(frame->data[2] + i * frame->linesize[2]);
  57
  58         for (int j = 0; j < avctx->width; j += 2) {
  59             /* u, y0, v, y1 */
  60             put_bits(&pb, 10, av_clip_uintp2(*u++, 10));
  61             put_bits(&pb, 10, av_clip_uintp2(*y++, 10));
  62             put_bits(&pb, 10, av_clip_uintp2(*v++, 10));
  63             put_bits(&pb, 10, av_clip_uintp2(*y++, 10));
  64         }
  65     }
  66     flush_put_bits(&pb);
  67
  68     return 0;
  69 }
  70
  71
  72 static av_cold int encode_init(AVCodecContext *avctx)
  73 {
  74     struct BitpackedContext *s = avctx->priv_data;
  75     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(avctx->pix_fmt);
  76
  77     if (avctx->width & 1) {
  78         av_log(avctx, AV_LOG_ERROR, "bitpacked needs even width\n");
  79         return AVERROR(EINVAL);
  80     }
  81
  82     avctx->bits_per_coded_sample = av_get_bits_per_pixel(desc);
  83     avctx->bit_rate = ff_guess_coded_bitrate(avctx);
  84
  85     if (avctx->pix_fmt == AV_PIX_FMT_YUV422P10)
  86         s->encode = encode_yuv422p10;
  87     else
  88         return AVERROR(EINVAL);
  89
  90     return 0;
  91 }
  92
  93 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
  94                         const AVFrame *frame, int *got_packet)
  95 {
  96     struct BitpackedContext *s = avctx->priv_data;
  97     int ret;
  98
  99     ret = s->encode(avctx, pkt, frame);
 100     if (ret)
 101         return ret;
 102
 103     *got_packet = 1;
 104     return 0;
 105 }
 106
 107 const FFCodec ff_bitpacked_encoder = {
 108     .p.name         = "bitpacked",
 109     .p.long_name    = NULL_IF_CONFIG_SMALL("Bitpacked"),
 110     .p.type         = AVMEDIA_TYPE_VIDEO,
 111     .p.id           = AV_CODEC_ID_BITPACKED,
 112     .priv_data_size = sizeof(struct BitpackedContext),
 113     .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
 114     .init           = encode_init,
 115     FF_CODEC_ENCODE_CB(encode_frame),
 116     .p.pix_fmts     = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV422P10,
 117                                                     AV_PIX_FMT_NONE },
 118     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
 119 };