1/*
2 * VC3/DNxHD decoder.
3 * Copyright (c) 2007 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>
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//#define TRACE
23//#define DEBUG
24
25#include "avcodec.h"
26#include "get_bits.h"
27#include "dnxhddata.h"
28#include "dsputil.h"
29
30typedef struct {
31    AVCodecContext *avctx;
32    AVFrame picture;
33    GetBitContext gb;
34    int cid;                            ///< compression id
35    unsigned int width, height;
36    unsigned int mb_width, mb_height;
37    uint32_t mb_scan_index[68];         /* max for 1080p */
38    int cur_field;                      ///< current interlaced field
39    VLC ac_vlc, dc_vlc, run_vlc;
40    int last_dc[3];
41    DSPContext dsp;
42    DECLARE_ALIGNED(16, DCTELEM, blocks)[8][64];
43    ScanTable scantable;
44    const CIDEntry *cid_table;
45} DNXHDContext;
46
47#define DNXHD_VLC_BITS 9
48#define DNXHD_DC_VLC_BITS 7
49
50static av_cold int dnxhd_decode_init(AVCodecContext *avctx)
51{
52    DNXHDContext *ctx = avctx->priv_data;
53
54    ctx->avctx = avctx;
55    dsputil_init(&ctx->dsp, avctx);
56    avctx->coded_frame = &ctx->picture;
57    ctx->picture.type = FF_I_TYPE;
58    return 0;
59}
60
61static int dnxhd_init_vlc(DNXHDContext *ctx, int cid)
62{
63    if (!ctx->cid_table) {
64        int index;
65
66        if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {
67            av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %d\n", cid);
68            return -1;
69        }
70        ctx->cid_table = &ff_dnxhd_cid_table[index];
71        init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,
72                 ctx->cid_table->ac_bits, 1, 1,
73                 ctx->cid_table->ac_codes, 2, 2, 0);
74        init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, ctx->cid_table->bit_depth+4,
75                 ctx->cid_table->dc_bits, 1, 1,
76                 ctx->cid_table->dc_codes, 1, 1, 0);
77        init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,
78                 ctx->cid_table->run_bits, 1, 1,
79                 ctx->cid_table->run_codes, 2, 2, 0);
80
81        ff_init_scantable(ctx->dsp.idct_permutation, &ctx->scantable, ff_zigzag_direct);
82    }
83    return 0;
84}
85
86static int dnxhd_decode_header(DNXHDContext *ctx, const uint8_t *buf, int buf_size, int first_field)
87{
88    static const uint8_t header_prefix[] = { 0x00, 0x00, 0x02, 0x80, 0x01 };
89    int i;
90
91    if (buf_size < 0x280)
92        return -1;
93
94    if (memcmp(buf, header_prefix, 5)) {
95        av_log(ctx->avctx, AV_LOG_ERROR, "error in header\n");
96        return -1;
97    }
98    if (buf[5] & 2) { /* interlaced */
99        ctx->cur_field = buf[5] & 1;
100        ctx->picture.interlaced_frame = 1;
101        ctx->picture.top_field_first = first_field ^ ctx->cur_field;
102        av_log(ctx->avctx, AV_LOG_DEBUG, "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);
103    }
104
105    ctx->height = AV_RB16(buf + 0x18);
106    ctx->width  = AV_RB16(buf + 0x1a);
107
108    dprintf(ctx->avctx, "width %d, heigth %d\n", ctx->width, ctx->height);
109
110    if (buf[0x21] & 0x40) {
111        av_log(ctx->avctx, AV_LOG_ERROR, "10 bit per component\n");
112        return -1;
113    }
114
115    ctx->cid = AV_RB32(buf + 0x28);
116    dprintf(ctx->avctx, "compression id %d\n", ctx->cid);
117
118    if (dnxhd_init_vlc(ctx, ctx->cid) < 0)
119        return -1;
120
121    if (buf_size < ctx->cid_table->coding_unit_size) {
122        av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size\n");
123        return -1;
124    }
125
126    ctx->mb_width = ctx->width>>4;
127    ctx->mb_height = buf[0x16d];
128
129    dprintf(ctx->avctx, "mb width %d, mb height %d\n", ctx->mb_width, ctx->mb_height);
130
131    if ((ctx->height+15)>>4 == ctx->mb_height && ctx->picture.interlaced_frame)
132        ctx->height <<= 1;
133
134    if (ctx->mb_height > 68 ||
135        (ctx->mb_height<<ctx->picture.interlaced_frame) > (ctx->height+15)>>4) {
136        av_log(ctx->avctx, AV_LOG_ERROR, "mb height too big: %d\n", ctx->mb_height);
137        return -1;
138    }
139
140    for (i = 0; i < ctx->mb_height; i++) {
141        ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i<<2));
142        dprintf(ctx->avctx, "mb scan index %d\n", ctx->mb_scan_index[i]);
143        if (buf_size < ctx->mb_scan_index[i] + 0x280) {
144            av_log(ctx->avctx, AV_LOG_ERROR, "invalid mb scan index\n");
145            return -1;
146        }
147    }
148
149    return 0;
150}
151
152static int dnxhd_decode_dc(DNXHDContext *ctx)
153{
154    int len;
155
156    len = get_vlc2(&ctx->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
157    return len ? get_xbits(&ctx->gb, len) : 0;
158}
159
160static void dnxhd_decode_dct_block(DNXHDContext *ctx, DCTELEM *block, int n, int qscale)
161{
162    int i, j, index, index2;
163    int level, component, sign;
164    const uint8_t *weigth_matrix;
165
166    if (n&2) {
167        component = 1 + (n&1);
168        weigth_matrix = ctx->cid_table->chroma_weight;
169    } else {
170        component = 0;
171        weigth_matrix = ctx->cid_table->luma_weight;
172    }
173
174    ctx->last_dc[component] += dnxhd_decode_dc(ctx);
175    block[0] = ctx->last_dc[component];
176    //av_log(ctx->avctx, AV_LOG_DEBUG, "dc %d\n", block[0]);
177    for (i = 1; ; i++) {
178        index = get_vlc2(&ctx->gb, ctx->ac_vlc.table, DNXHD_VLC_BITS, 2);
179        //av_log(ctx->avctx, AV_LOG_DEBUG, "index %d\n", index);
180        level = ctx->cid_table->ac_level[index];
181        if (!level) { /* EOB */
182            //av_log(ctx->avctx, AV_LOG_DEBUG, "EOB\n");
183            return;
184        }
185        sign = get_sbits(&ctx->gb, 1);
186
187        if (ctx->cid_table->ac_index_flag[index]) {
188            level += get_bits(&ctx->gb, ctx->cid_table->index_bits)<<6;
189        }
190
191        if (ctx->cid_table->ac_run_flag[index]) {
192            index2 = get_vlc2(&ctx->gb, ctx->run_vlc.table, DNXHD_VLC_BITS, 2);
193            i += ctx->cid_table->run[index2];
194        }
195
196        if (i > 63) {
197            av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);
198            return;
199        }
200
201        j = ctx->scantable.permutated[i];
202        //av_log(ctx->avctx, AV_LOG_DEBUG, "j %d\n", j);
203        //av_log(ctx->avctx, AV_LOG_DEBUG, "level %d, weigth %d\n", level, weigth_matrix[i]);
204        level = (2*level+1) * qscale * weigth_matrix[i];
205        if (ctx->cid_table->bit_depth == 10) {
206            if (weigth_matrix[i] != 8)
207                level += 8;
208            level >>= 4;
209        } else {
210            if (weigth_matrix[i] != 32)
211                level += 32;
212            level >>= 6;
213        }
214        //av_log(NULL, AV_LOG_DEBUG, "i %d, j %d, end level %d\n", i, j, level);
215        block[j] = (level^sign) - sign;
216    }
217}
218
219static int dnxhd_decode_macroblock(DNXHDContext *ctx, int x, int y)
220{
221    int dct_linesize_luma   = ctx->picture.linesize[0];
222    int dct_linesize_chroma = ctx->picture.linesize[1];
223    uint8_t *dest_y, *dest_u, *dest_v;
224    int dct_offset;
225    int qscale, i;
226
227    qscale = get_bits(&ctx->gb, 11);
228    skip_bits1(&ctx->gb);
229    //av_log(ctx->avctx, AV_LOG_DEBUG, "qscale %d\n", qscale);
230
231    for (i = 0; i < 8; i++) {
232        ctx->dsp.clear_block(ctx->blocks[i]);
233        dnxhd_decode_dct_block(ctx, ctx->blocks[i], i, qscale);
234    }
235
236    if (ctx->picture.interlaced_frame) {
237        dct_linesize_luma   <<= 1;
238        dct_linesize_chroma <<= 1;
239    }
240
241    dest_y = ctx->picture.data[0] + ((y * dct_linesize_luma)   << 4) + (x << 4);
242    dest_u = ctx->picture.data[1] + ((y * dct_linesize_chroma) << 4) + (x << 3);
243    dest_v = ctx->picture.data[2] + ((y * dct_linesize_chroma) << 4) + (x << 3);
244
245    if (ctx->cur_field) {
246        dest_y += ctx->picture.linesize[0];
247        dest_u += ctx->picture.linesize[1];
248        dest_v += ctx->picture.linesize[2];
249    }
250
251    dct_offset = dct_linesize_luma << 3;
252    ctx->dsp.idct_put(dest_y,                  dct_linesize_luma, ctx->blocks[0]);
253    ctx->dsp.idct_put(dest_y + 8,              dct_linesize_luma, ctx->blocks[1]);
254    ctx->dsp.idct_put(dest_y + dct_offset,     dct_linesize_luma, ctx->blocks[4]);
255    ctx->dsp.idct_put(dest_y + dct_offset + 8, dct_linesize_luma, ctx->blocks[5]);
256
257    if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
258        dct_offset = dct_linesize_chroma << 3;
259        ctx->dsp.idct_put(dest_u,              dct_linesize_chroma, ctx->blocks[2]);
260        ctx->dsp.idct_put(dest_v,              dct_linesize_chroma, ctx->blocks[3]);
261        ctx->dsp.idct_put(dest_u + dct_offset, dct_linesize_chroma, ctx->blocks[6]);
262        ctx->dsp.idct_put(dest_v + dct_offset, dct_linesize_chroma, ctx->blocks[7]);
263    }
264
265    return 0;
266}
267
268static int dnxhd_decode_macroblocks(DNXHDContext *ctx, const uint8_t *buf, int buf_size)
269{
270    int x, y;
271    for (y = 0; y < ctx->mb_height; y++) {
272        ctx->last_dc[0] =
273        ctx->last_dc[1] =
274        ctx->last_dc[2] = 1<<(ctx->cid_table->bit_depth+2); // for levels +2^(bitdepth-1)
275        init_get_bits(&ctx->gb, buf + ctx->mb_scan_index[y], (buf_size - ctx->mb_scan_index[y]) << 3);
276        for (x = 0; x < ctx->mb_width; x++) {
277            //START_TIMER;
278            dnxhd_decode_macroblock(ctx, x, y);
279            //STOP_TIMER("decode macroblock");
280        }
281    }
282    return 0;
283}
284
285static int dnxhd_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
286                              AVPacket *avpkt)
287{
288    const uint8_t *buf = avpkt->data;
289    int buf_size = avpkt->size;
290    DNXHDContext *ctx = avctx->priv_data;
291    AVFrame *picture = data;
292    int first_field = 1;
293
294    dprintf(avctx, "frame size %d\n", buf_size);
295
296 decode_coding_unit:
297    if (dnxhd_decode_header(ctx, buf, buf_size, first_field) < 0)
298        return -1;
299
300    if ((avctx->width || avctx->height) &&
301        (ctx->width != avctx->width || ctx->height != avctx->height)) {
302        av_log(avctx, AV_LOG_WARNING, "frame size changed: %dx%d -> %dx%d\n",
303               avctx->width, avctx->height, ctx->width, ctx->height);
304        first_field = 1;
305    }
306
307    avctx->pix_fmt = PIX_FMT_YUV422P;
308    if (avcodec_check_dimensions(avctx, ctx->width, ctx->height))
309        return -1;
310    avcodec_set_dimensions(avctx, ctx->width, ctx->height);
311
312    if (first_field) {
313        if (ctx->picture.data[0])
314            avctx->release_buffer(avctx, &ctx->picture);
315        if (avctx->get_buffer(avctx, &ctx->picture) < 0) {
316            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
317            return -1;
318        }
319    }
320
321    dnxhd_decode_macroblocks(ctx, buf + 0x280, buf_size - 0x280);
322
323    if (first_field && ctx->picture.interlaced_frame) {
324        buf      += ctx->cid_table->coding_unit_size;
325        buf_size -= ctx->cid_table->coding_unit_size;
326        first_field = 0;
327        goto decode_coding_unit;
328    }
329
330    *picture = ctx->picture;
331    *data_size = sizeof(AVPicture);
332    return buf_size;
333}
334
335static av_cold int dnxhd_decode_close(AVCodecContext *avctx)
336{
337    DNXHDContext *ctx = avctx->priv_data;
338
339    if (ctx->picture.data[0])
340        avctx->release_buffer(avctx, &ctx->picture);
341    free_vlc(&ctx->ac_vlc);
342    free_vlc(&ctx->dc_vlc);
343    free_vlc(&ctx->run_vlc);
344    return 0;
345}
346
347AVCodec dnxhd_decoder = {
348    "dnxhd",
349    AVMEDIA_TYPE_VIDEO,
350    CODEC_ID_DNXHD,
351    sizeof(DNXHDContext),
352    dnxhd_decode_init,
353    NULL,
354    dnxhd_decode_close,
355    dnxhd_decode_frame,
356    CODEC_CAP_DR1,
357    .long_name = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),
358};
359