lavc decoders: work with refcounted frames.
[libav.git] / libavcodec / bethsoftvideo.c
1 /*
2 * Bethesda VID video decoder
3 * Copyright (C) 2007 Nicholas Tung
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 * @brief Bethesda Softworks VID Video Decoder
25 * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
26 * @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
27 * @see http://www.svatopluk.com/andux/docs/dfvid.html
28 */
29
30 #include "libavutil/common.h"
31 #include "avcodec.h"
32 #include "bethsoftvideo.h"
33 #include "bytestream.h"
34 #include "internal.h"
35
36 typedef struct BethsoftvidContext {
37 AVFrame frame;
38 GetByteContext g;
39 } BethsoftvidContext;
40
41 static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
42 {
43 BethsoftvidContext *vid = avctx->priv_data;
44 avctx->pix_fmt = AV_PIX_FMT_PAL8;
45 return 0;
46 }
47
48 static int set_palette(BethsoftvidContext *ctx)
49 {
50 uint32_t *palette = (uint32_t *)ctx->frame.data[1];
51 int a;
52
53 if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
54 return AVERROR_INVALIDDATA;
55
56 for(a = 0; a < 256; a++){
57 palette[a] = bytestream2_get_be24u(&ctx->g) * 4;
58 }
59 ctx->frame.palette_has_changed = 1;
60 return 0;
61 }
62
63 static int bethsoftvid_decode_frame(AVCodecContext *avctx,
64 void *data, int *got_frame,
65 AVPacket *avpkt)
66 {
67 BethsoftvidContext * vid = avctx->priv_data;
68 char block_type;
69 uint8_t * dst;
70 uint8_t * frame_end;
71 int remaining = avctx->width; // number of bytes remaining on a line
72 int wrap_to_next_line;
73 int code, ret;
74 int yoffset;
75
76 if ((ret = ff_reget_buffer(avctx, &vid->frame)) < 0) {
77 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
78 return ret;
79 }
80 wrap_to_next_line = vid->frame.linesize[0] - avctx->width;
81
82 if (avpkt->side_data_elems > 0 &&
83 avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) {
84 bytestream2_init(&vid->g, avpkt->side_data[0].data,
85 avpkt->side_data[0].size);
86 if ((ret = set_palette(vid)) < 0)
87 return ret;
88 }
89
90 bytestream2_init(&vid->g, avpkt->data, avpkt->size);
91 dst = vid->frame.data[0];
92 frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height;
93
94 switch(block_type = bytestream2_get_byte(&vid->g)){
95 case PALETTE_BLOCK: {
96 *got_frame = 0;
97 if ((ret = set_palette(vid)) < 0) {
98 av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
99 return ret;
100 }
101 return bytestream2_tell(&vid->g);
102 }
103 case VIDEO_YOFF_P_FRAME:
104 yoffset = bytestream2_get_le16(&vid->g);
105 if(yoffset >= avctx->height)
106 return AVERROR_INVALIDDATA;
107 dst += vid->frame.linesize[0] * yoffset;
108 }
109
110 // main code
111 while((code = bytestream2_get_byte(&vid->g))){
112 int length = code & 0x7f;
113
114 // copy any bytes starting at the current position, and ending at the frame width
115 while(length > remaining){
116 if(code < 0x80)
117 bytestream2_get_buffer(&vid->g, dst, remaining);
118 else if(block_type == VIDEO_I_FRAME)
119 memset(dst, bytestream2_peek_byte(&vid->g), remaining);
120 length -= remaining; // decrement the number of bytes to be copied
121 dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
122 remaining = avctx->width;
123 if(dst == frame_end)
124 goto end;
125 }
126
127 // copy any remaining bytes after / if line overflows
128 if(code < 0x80)
129 bytestream2_get_buffer(&vid->g, dst, length);
130 else if(block_type == VIDEO_I_FRAME)
131 memset(dst, bytestream2_get_byte(&vid->g), length);
132 remaining -= length;
133 dst += length;
134 }
135 end:
136
137 if ((ret = av_frame_ref(data, &vid->frame)) < 0)
138 return ret;
139
140 *got_frame = 1;
141
142 return avpkt->size;
143 }
144
145 static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
146 {
147 BethsoftvidContext * vid = avctx->priv_data;
148 av_frame_unref(&vid->frame);
149 return 0;
150 }
151
152 AVCodec ff_bethsoftvid_decoder = {
153 .name = "bethsoftvid",
154 .type = AVMEDIA_TYPE_VIDEO,
155 .id = AV_CODEC_ID_BETHSOFTVID,
156 .priv_data_size = sizeof(BethsoftvidContext),
157 .init = bethsoftvid_decode_init,
158 .close = bethsoftvid_decode_end,
159 .decode = bethsoftvid_decode_frame,
160 .capabilities = CODEC_CAP_DR1,
161 .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),
162 };