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
30struct BitpackedContext {
31    int (*encode)(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *frame);
32};
33
34static 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
72static 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
93static 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
107const 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};
120