xref: /third_party/ffmpeg/libavcodec/avrndec.c (revision cabdff1a)
1/*
2 * AVRn decoder
3 * Copyright (c) 2012 Michael Niedermayer
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#include "avcodec.h"
23#include "codec_internal.h"
24#include "internal.h"
25#include "libavutil/imgutils.h"
26
27typedef struct {
28    int interlace;
29    int tff;
30} AVRnContext;
31
32static av_cold int init(AVCodecContext *avctx)
33{
34    AVRnContext *a = avctx->priv_data;
35    int ret;
36
37    if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
38        return ret;
39
40    avctx->pix_fmt = AV_PIX_FMT_UYVY422;
41
42    if(avctx->extradata_size >= 9 && avctx->extradata[4]+28 < avctx->extradata_size) {
43        int ndx = avctx->extradata[4] + 4;
44        a->interlace = !memcmp(avctx->extradata + ndx, "1:1(", 4);
45        if(a->interlace) {
46            a->tff = avctx->extradata[ndx + 24] == 1;
47        }
48    }
49
50    return 0;
51}
52
53static int decode_frame(AVCodecContext *avctx, AVFrame *p,
54                        int *got_frame, AVPacket *avpkt)
55{
56    AVRnContext *a = avctx->priv_data;
57    const uint8_t *buf = avpkt->data;
58    int buf_size       = avpkt->size;
59    int y, ret, true_height;
60
61    true_height    = buf_size / (2*avctx->width);
62
63    if(buf_size < 2*avctx->width * avctx->height) {
64        av_log(avctx, AV_LOG_ERROR, "packet too small\n");
65        return AVERROR_INVALIDDATA;
66    }
67
68    if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
69        return ret;
70    p->pict_type= AV_PICTURE_TYPE_I;
71    p->key_frame= 1;
72
73    if(a->interlace) {
74        buf += (true_height - avctx->height)*avctx->width;
75        for(y = 0; y < avctx->height-1; y+=2) {
76            memcpy(p->data[0] + (y+ a->tff)*p->linesize[0], buf                             , 2*avctx->width);
77            memcpy(p->data[0] + (y+!a->tff)*p->linesize[0], buf + avctx->width*true_height+4, 2*avctx->width);
78            buf += 2*avctx->width;
79        }
80    } else {
81        buf += (true_height - avctx->height)*avctx->width*2;
82        for(y = 0; y < avctx->height; y++) {
83            memcpy(p->data[0] + y*p->linesize[0], buf, 2*avctx->width);
84            buf += 2*avctx->width;
85        }
86    }
87
88    *got_frame      = 1;
89    return buf_size;
90}
91
92const FFCodec ff_avrn_decoder = {
93    .p.name         = "avrn",
94    .p.long_name    = NULL_IF_CONFIG_SMALL("Avid AVI Codec"),
95    .p.type         = AVMEDIA_TYPE_VIDEO,
96    .p.id           = AV_CODEC_ID_AVRN,
97    .priv_data_size = sizeof(AVRnContext),
98    .init           = init,
99    FF_CODEC_DECODE_CB(decode_frame),
100    .p.capabilities = AV_CODEC_CAP_DR1,
101    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
102};
103