lavc: add a wrapper for AVCodecContext.get_buffer().
[libav.git] / libavcodec / vble.c
1 /*
2 * VBLE Decoder
3 * Copyright (c) 2011 Derek Buitenhuis
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 * VBLE Decoder
25 */
26
27 #define BITSTREAM_READER_LE
28
29 #include "avcodec.h"
30 #include "dsputil.h"
31 #include "get_bits.h"
32 #include "internal.h"
33 #include "mathops.h"
34
35 typedef struct {
36 AVCodecContext *avctx;
37 DSPContext dsp;
38
39 int size;
40 uint8_t *val; /* First holds the lengths of vlc symbols and then their values */
41 } VBLEContext;
42
43 static uint8_t vble_read_reverse_unary(GetBitContext *gb)
44 {
45 /* At most we need to read 9 bits total to get indices up to 8 */
46 uint8_t val = show_bits(gb, 8);
47
48 if (val) {
49 val = 7 - av_log2_16bit(ff_reverse[val]);
50 skip_bits(gb, val + 1);
51 return val;
52 } else {
53 skip_bits(gb, 8);
54 if (get_bits1(gb))
55 return 8;
56 }
57
58 /* Return something larger than 8 on error */
59 return UINT8_MAX;
60 }
61
62 static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
63 {
64 int i;
65
66 /* Read all the lengths in first */
67 for (i = 0; i < ctx->size; i++) {
68 ctx->val[i] = vble_read_reverse_unary(gb);
69
70 if (ctx->val[i] == UINT8_MAX)
71 return -1;
72 }
73
74 for (i = 0; i < ctx->size; i++) {
75 /* Check we have enough bits left */
76 if (get_bits_left(gb) < ctx->val[i])
77 return -1;
78
79 /* get_bits can't take a length of 0 */
80 if (ctx->val[i])
81 ctx->val[i] = (1 << ctx->val[i]) + get_bits(gb, ctx->val[i]) - 1;
82 }
83
84 return 0;
85 }
86
87 static void vble_restore_plane(VBLEContext *ctx, int plane, int offset,
88 int width, int height)
89 {
90 AVFrame *pic = ctx->avctx->coded_frame;
91 uint8_t *dst = pic->data[plane];
92 uint8_t *val = ctx->val + offset;
93 int stride = pic->linesize[plane];
94 int i, j, left, left_top;
95
96 for (i = 0; i < height; i++) {
97 for (j = 0; j < width; j++)
98 val[j] = (val[j] >> 1) ^ -(val[j] & 1);
99
100 if (i) {
101 left = 0;
102 left_top = dst[-stride];
103 ctx->dsp.add_hfyu_median_prediction(dst, dst-stride, val,
104 width, &left, &left_top);
105 } else {
106 dst[0] = val[0];
107 for (j = 1; j < width; j++)
108 dst[j] = val[j] + dst[j - 1];
109 }
110 dst += stride;
111 val += width;
112 }
113 }
114
115 static int vble_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
116 AVPacket *avpkt)
117 {
118 VBLEContext *ctx = avctx->priv_data;
119 AVFrame *pic = avctx->coded_frame;
120 GetBitContext gb;
121 const uint8_t *src = avpkt->data;
122 int version;
123 int offset = 0;
124 int width_uv = avctx->width / 2, height_uv = avctx->height / 2;
125
126 pic->reference = 0;
127
128 /* Clear buffer if need be */
129 if (pic->data[0])
130 avctx->release_buffer(avctx, pic);
131
132 /* Allocate buffer */
133 if (ff_get_buffer(avctx, pic) < 0) {
134 av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
135 return AVERROR(ENOMEM);
136 }
137
138 /* Set flags */
139 pic->key_frame = 1;
140 pic->pict_type = AV_PICTURE_TYPE_I;
141
142 /* Version should always be 1 */
143 version = AV_RL32(src);
144
145 if (version != 1)
146 av_log(avctx, AV_LOG_WARNING, "Unsupported VBLE Version: %d\n", version);
147
148 init_get_bits(&gb, src + 4, (avpkt->size - 4) * 8);
149
150 /* Unpack */
151 if (vble_unpack(ctx, &gb) < 0) {
152 av_log(avctx, AV_LOG_ERROR, "Invalid Code\n");
153 return AVERROR_INVALIDDATA;
154 }
155
156 /* Restore planes. Should be almost identical to Huffyuv's. */
157 vble_restore_plane(ctx, 0, offset, avctx->width, avctx->height);
158
159 /* Chroma */
160 if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
161 offset += avctx->width * avctx->height;
162 vble_restore_plane(ctx, 1, offset, width_uv, height_uv);
163
164 offset += width_uv * height_uv;
165 vble_restore_plane(ctx, 2, offset, width_uv, height_uv);
166 }
167
168 *data_size = sizeof(AVFrame);
169 *(AVFrame *)data = *pic;
170
171 return avpkt->size;
172 }
173
174 static av_cold int vble_decode_close(AVCodecContext *avctx)
175 {
176 VBLEContext *ctx = avctx->priv_data;
177 AVFrame *pic = avctx->coded_frame;
178
179 if (pic->data[0])
180 avctx->release_buffer(avctx, pic);
181
182 av_freep(&avctx->coded_frame);
183 av_freep(&ctx->val);
184
185 return 0;
186 }
187
188 static av_cold int vble_decode_init(AVCodecContext *avctx)
189 {
190 VBLEContext *ctx = avctx->priv_data;
191
192 /* Stash for later use */
193 ctx->avctx = avctx;
194 ff_dsputil_init(&ctx->dsp, avctx);
195
196 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
197 avctx->bits_per_raw_sample = 8;
198 avctx->coded_frame = avcodec_alloc_frame();
199
200 if (!avctx->coded_frame) {
201 av_log(avctx, AV_LOG_ERROR, "Could not allocate frame.\n");
202 return AVERROR(ENOMEM);
203 }
204
205 ctx->size = avpicture_get_size(avctx->pix_fmt,
206 avctx->width, avctx->height);
207
208 ctx->val = av_malloc(ctx->size * sizeof(*ctx->val));
209
210 if (!ctx->val) {
211 av_log(avctx, AV_LOG_ERROR, "Could not allocate values buffer.\n");
212 vble_decode_close(avctx);
213 return AVERROR(ENOMEM);
214 }
215
216 return 0;
217 }
218
219 AVCodec ff_vble_decoder = {
220 .name = "vble",
221 .type = AVMEDIA_TYPE_VIDEO,
222 .id = AV_CODEC_ID_VBLE,
223 .priv_data_size = sizeof(VBLEContext),
224 .init = vble_decode_init,
225 .close = vble_decode_close,
226 .decode = vble_decode_frame,
227 .capabilities = CODEC_CAP_DR1,
228 .long_name = NULL_IF_CONFIG_SMALL("VBLE Lossless Codec"),
229 };