3 * Copyright (c) 2004 Konstantin Shishkov
5 * This file is part of FFmpeg.
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.
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.
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
28 #include "bytestream.h"
31 typedef struct QpegContext{
32 AVCodecContext *avctx;
35 GetByteContext buffer;
38 static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
39 int stride, int width, int height)
50 dst = dst + height * stride;
52 while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) {
53 code = bytestream2_get_byte(&qctx->buffer);
55 if(code == 0xFC) /* end-of-picture code */
57 if(code >= 0xF8) { /* very long run */
58 c0 = bytestream2_get_byte(&qctx->buffer);
59 c1 = bytestream2_get_byte(&qctx->buffer);
60 run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
61 } else if (code >= 0xF0) { /* long run */
62 c0 = bytestream2_get_byte(&qctx->buffer);
63 run = ((code & 0xF) << 8) + c0 + 2;
64 } else if (code >= 0xE0) { /* short run */
65 run = (code & 0x1F) + 2;
66 } else if (code >= 0xC0) { /* very long copy */
67 c0 = bytestream2_get_byte(&qctx->buffer);
68 c1 = bytestream2_get_byte(&qctx->buffer);
69 copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
70 } else if (code >= 0x80) { /* long copy */
71 c0 = bytestream2_get_byte(&qctx->buffer);
72 copy = ((code & 0x7F) << 8) + c0 + 1;
73 } else { /* short copy */
77 /* perform actual run or copy */
81 p = bytestream2_get_byte(&qctx->buffer);
82 for(i = 0; i < run; i++) {
84 if (filled >= width) {
93 for(i = 0; i < copy; i++) {
94 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
95 if (filled >= width) {
107 static const int qpeg_table_h[16] =
108 { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
109 static const int qpeg_table_w[16] =
110 { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
112 /* Decodes delta frames */
113 static void qpeg_decode_inter(QpegContext *qctx, uint8_t *dst,
114 int stride, int width, int height,
115 int delta, const uint8_t *ctable,
126 /* copy prev frame */
127 for(i = 0; i < height; i++)
128 memcpy(dst + (i * stride), refdata + (i * stride), width);
130 orig_height = height;
132 dst = dst + height * stride;
134 while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) {
135 code = bytestream2_get_byte(&qctx->buffer);
138 /* motion compensation */
139 while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) {
142 int me_w, me_h, me_x, me_y;
146 /* get block size by index */
148 me_w = qpeg_table_w[me_idx];
149 me_h = qpeg_table_h[me_idx];
151 /* extract motion vector */
152 corr = bytestream2_get_byte(&qctx->buffer);
164 /* check motion vector */
165 if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
166 (height - me_y - me_h < 0) || (height - me_y > orig_height) ||
167 (filled + me_w > width) || (height - me_h < 0))
168 av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
169 me_x, me_y, me_w, me_h, filled, height);
171 /* do motion compensation */
172 me_plane = refdata + (filled + me_x) + (height - me_y) * stride;
173 for(j = 0; j < me_h; j++) {
174 for(i = 0; i < me_w; i++)
175 dst[filled + i - (j * stride)] = me_plane[i - (j * stride)];
179 code = bytestream2_get_byte(&qctx->buffer);
183 if(code == 0xE0) /* end-of-picture code */
185 if(code > 0xE0) { /* run code: 0xE1..0xFF */
189 p = bytestream2_get_byte(&qctx->buffer);
190 for(i = 0; i <= code; i++) {
192 if(filled >= width) {
200 } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
203 if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer))
206 for(i = 0; i <= code; i++) {
207 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
208 if(filled >= width) {
216 } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
220 /* codes 0x80 and 0x81 are actually escape codes,
221 skip value minus constant is in the next byte */
223 skip = bytestream2_get_byte(&qctx->buffer) + 64;
225 skip = bytestream2_get_byte(&qctx->buffer) + 320;
229 while( filled >= width) {
237 /* zero code treated as one-pixel skip */
239 dst[filled++] = ctable[code & 0x7F];
243 if(filled >= width) {
252 static int decode_frame(AVCodecContext *avctx,
253 void *data, int *got_frame,
257 QpegContext * const a = avctx->priv_data;
258 AVFrame * p = &a->pic;
259 AVFrame * ref= &a->ref;
262 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
264 if (avpkt->size < 0x86) {
265 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
266 return AVERROR_INVALIDDATA;
269 bytestream2_init(&a->buffer, avpkt->data, avpkt->size);
272 av_frame_move_ref(ref, p);
274 if ((ret = ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF)) < 0)
276 outdata = a->pic.data[0];
277 bytestream2_skip(&a->buffer, 4);
278 bytestream2_get_buffer(&a->buffer, ctable, 128);
279 bytestream2_skip(&a->buffer, 1);
281 delta = bytestream2_get_byte(&a->buffer);
283 qpeg_decode_intra(a, outdata, a->pic.linesize[0], avctx->width, avctx->height);
285 qpeg_decode_inter(a, outdata, a->pic.linesize[0], avctx->width, avctx->height, delta, ctable, a->ref.data[0]);
288 /* make the palette available on the way out */
290 a->pic.palette_has_changed = 1;
291 memcpy(a->pal, pal, AVPALETTE_SIZE);
293 memcpy(a->pic.data[1], a->pal, AVPALETTE_SIZE);
295 if ((ret = av_frame_ref(data, &a->pic)) < 0)
303 static void decode_flush(AVCodecContext *avctx){
304 QpegContext * const a = avctx->priv_data;
306 const uint8_t *pal_src;
308 pal_size = FFMIN(1024U, avctx->extradata_size);
309 pal_src = avctx->extradata + avctx->extradata_size - pal_size;
311 for (i=0; i<pal_size/4; i++)
312 a->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
315 static av_cold int decode_init(AVCodecContext *avctx){
316 QpegContext * const a = avctx->priv_data;
318 avcodec_get_frame_defaults(&a->pic);
319 avcodec_get_frame_defaults(&a->ref);
321 avctx->pix_fmt= AV_PIX_FMT_PAL8;
325 avcodec_get_frame_defaults(&a->pic);
330 static av_cold int decode_end(AVCodecContext *avctx){
331 QpegContext * const a = avctx->priv_data;
332 AVFrame * const p = &a->pic;
333 AVFrame * const ref= &a->ref;
341 AVCodec ff_qpeg_decoder = {
343 .type = AVMEDIA_TYPE_VIDEO,
344 .id = AV_CODEC_ID_QPEG,
345 .priv_data_size = sizeof(QpegContext),
348 .decode = decode_frame,
349 .flush = decode_flush,
350 .capabilities = CODEC_CAP_DR1,
351 .long_name = NULL_IF_CONFIG_SMALL("Q-team QPEG"),