2 * WinCAM Motion Video decoder
4 * Copyright (c) 2018 Paul B Mahol
6 * This file is part of FFmpeg.
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.
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.
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
27 #include "libavutil/imgutils.h"
30 #include "bytestream.h"
35 typedef struct WCMVContext {
39 uint8_t block_data[65536*8];
42 static int decode_frame(AVCodecContext *avctx,
43 void *data, int *got_frame,
46 WCMVContext *s = avctx->priv_data;
47 AVFrame *frame = data;
48 int skip, blocks, zret, ret, intra = 0, bpp = s->bpp;
52 ret = inflateReset(&s->zstream);
54 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
55 return AVERROR_EXTERNAL;
58 bytestream2_init(&gb, avpkt->data, avpkt->size);
60 if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
63 if (s->prev_frame->data[0]) {
64 ret = av_frame_copy(frame, s->prev_frame);
68 ptrdiff_t linesize[4] = { frame->linesize[0], 0, 0, 0 };
69 av_image_fill_black(frame->data, linesize, avctx->pix_fmt, 0,
70 avctx->width, avctx->height);
73 blocks = bytestream2_get_le16(&gb);
78 if (blocks * 8 >= 0xFFFF)
79 size = bytestream2_get_le24(&gb);
80 else if (blocks * 8 >= 0xFF)
81 size = bytestream2_get_le16(&gb);
83 size = bytestream2_get_byte(&gb);
85 skip = bytestream2_tell(&gb);
86 if (size > avpkt->size - skip)
87 return AVERROR_INVALIDDATA;
89 s->zstream.next_in = avpkt->data + skip;
90 s->zstream.avail_in = size;
91 s->zstream.next_out = s->block_data;
92 s->zstream.avail_out = sizeof(s->block_data);
94 zret = inflate(&s->zstream, Z_FINISH);
95 if (zret != Z_STREAM_END) {
96 av_log(avctx, AV_LOG_ERROR,
97 "Inflate failed with return code: %d.\n", zret);
98 return AVERROR_INVALIDDATA;
101 ret = inflateReset(&s->zstream);
103 av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
104 return AVERROR_EXTERNAL;
107 bytestream2_skip(&gb, size);
108 bytestream2_init(&bgb, s->block_data, blocks * 8);
110 for (int i = 0; i < blocks; i++) {
113 bytestream2_skip(&bgb, 4);
114 w = bytestream2_get_le16(&bgb);
115 h = bytestream2_get_le16(&bgb);
120 bytestream2_skip(&gb, 3);
122 bytestream2_skip(&gb, 2);
124 bytestream2_skip(&gb, 1);
126 skip = bytestream2_tell(&gb);
128 s->zstream.next_in = avpkt->data + skip;
129 s->zstream.avail_in = avpkt->size - skip;
131 bytestream2_init(&gb, s->block_data, blocks * 8);
135 bytestream2_seek(&gb, 2, SEEK_SET);
137 for (int i = 0; i < blocks; i++) {
140 bytestream2_skip(&gb, 4);
141 w = bytestream2_get_le16(&gb);
142 h = bytestream2_get_le16(&gb);
147 bytestream2_skip(&gb, 3);
149 bytestream2_skip(&gb, 2);
151 bytestream2_skip(&gb, 1);
153 skip = bytestream2_tell(&gb);
155 s->zstream.next_in = avpkt->data + skip;
156 s->zstream.avail_in = avpkt->size - skip;
158 bytestream2_seek(&gb, 2, SEEK_SET);
161 for (int block = 0; block < blocks; block++) {
164 x = bytestream2_get_le16(&gb);
165 y = bytestream2_get_le16(&gb);
166 w = bytestream2_get_le16(&gb);
167 h = bytestream2_get_le16(&gb);
169 if (blocks == 1 && x == 0 && y == 0 && w == avctx->width && h == avctx->height)
172 if (x + w > avctx->width || y + h > avctx->height)
173 return AVERROR_INVALIDDATA;
175 if (w > avctx->width || h > avctx->height)
176 return AVERROR_INVALIDDATA;
178 dst = frame->data[0] + (avctx->height - y - 1) * frame->linesize[0] + x * bpp;
179 for (int i = 0; i < h; i++) {
180 s->zstream.next_out = dst;
181 s->zstream.avail_out = w * bpp;
183 zret = inflate(&s->zstream, Z_SYNC_FLUSH);
184 if (zret != Z_OK && zret != Z_STREAM_END) {
185 av_log(avctx, AV_LOG_ERROR,
186 "Inflate failed with return code: %d.\n", zret);
187 return AVERROR_INVALIDDATA;
190 dst -= frame->linesize[0];
194 frame->key_frame = intra;
195 frame->pict_type = intra ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
197 av_frame_unref(s->prev_frame);
198 if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
206 static av_cold int decode_init(AVCodecContext *avctx)
208 WCMVContext *s = avctx->priv_data;
211 switch (avctx->bits_per_coded_sample) {
212 case 16: avctx->pix_fmt = AV_PIX_FMT_RGB565; break;
213 case 24: avctx->pix_fmt = AV_PIX_FMT_BGR24; break;
214 case 32: avctx->pix_fmt = AV_PIX_FMT_BGRA; break;
215 default: av_log(avctx, AV_LOG_ERROR, "Unsupported bits_per_coded_sample: %d\n",
216 avctx->bits_per_coded_sample);
217 return AVERROR_PATCHWELCOME;
220 s->bpp = avctx->bits_per_coded_sample >> 3;
222 s->zstream.zalloc = Z_NULL;
223 s->zstream.zfree = Z_NULL;
224 s->zstream.opaque = Z_NULL;
225 zret = inflateInit(&s->zstream);
227 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
228 return AVERROR_EXTERNAL;
231 s->prev_frame = av_frame_alloc();
233 return AVERROR(ENOMEM);
238 static av_cold int decode_close(AVCodecContext *avctx)
240 WCMVContext *s = avctx->priv_data;
242 av_frame_free(&s->prev_frame);
243 inflateEnd(&s->zstream);
248 AVCodec ff_wcmv_decoder = {
250 .long_name = NULL_IF_CONFIG_SMALL("WinCAM Motion Video"),
251 .type = AVMEDIA_TYPE_VIDEO,
252 .id = AV_CODEC_ID_WCMV,
253 .priv_data_size = sizeof(WCMVContext),
255 .close = decode_close,
256 .decode = decode_frame,
257 .capabilities = AV_CODEC_CAP_DR1,
258 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
259 FF_CODEC_CAP_INIT_CLEANUP,