xref: /third_party/ffmpeg/libavcodec/rv10.c (revision cabdff1a)
1/*
2 * RV10/RV20 decoder
3 * Copyright (c) 2000,2001 Fabrice Bellard
4 * Copyright (c) 2002-2004 Michael Niedermayer
5 *
6 * This file is part of FFmpeg.
7 *
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.
12 *
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.
17 *
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
21 */
22
23/**
24 * @file
25 * RV10/RV20 decoder
26 */
27
28#include <inttypes.h>
29
30#include "libavutil/imgutils.h"
31#include "libavutil/thread.h"
32
33#include "avcodec.h"
34#include "codec_internal.h"
35#include "error_resilience.h"
36#include "h263.h"
37#include "h263data.h"
38#include "h263dec.h"
39#include "internal.h"
40#include "mpeg_er.h"
41#include "mpegutils.h"
42#include "mpegvideo.h"
43#include "mpegvideodec.h"
44#include "mpeg4video.h"
45#include "mpegvideodata.h"
46#include "rv10dec.h"
47
48#define RV_GET_MAJOR_VER(x)  ((x) >> 28)
49#define RV_GET_MINOR_VER(x) (((x) >> 20) & 0xFF)
50#define RV_GET_MICRO_VER(x) (((x) >> 12) & 0xFF)
51
52#define MAX_VLC_ENTRIES 1023 // Note: Does not include the skip entries.
53#define DC_VLC_BITS        9
54
55typedef struct RVDecContext {
56    MpegEncContext m;
57    int sub_id;
58    int orig_width, orig_height;
59} RVDecContext;
60
61/* (run, length) encoded value for the symbols table. The actual symbols
62 * are run..run - length (mod 256).
63 * The last two entries in the following table apply to luma only.
64 * The skip values are not included in this list. */
65static const uint8_t rv_sym_run_len[][2] = {
66    {   0,   0 }, {   1,   0 }, { 255,   0 }, {   3,   1 }, { 254,  1 },
67    {   7,   3 }, { 252,   3 }, {  15,   7 }, { 248,   7 }, {  31, 15 },
68    { 240,  15 }, {  63,  31 }, { 224,  31 }, { 127,  63 }, { 192, 63 },
69    { 255, 127 }, { 128, 127 }, { 127, 255 }, { 128, 255 },
70};
71
72/* entry[i] of the following tables gives
73 * the number of VLC codes of length i + 2. */
74static const uint16_t rv_lum_len_count[15] = {
75    1,  0,  2,  4,  8, 16, 32,  0, 64,  0, 128,  0, 256,  0, 512,
76};
77
78static const uint16_t rv_chrom_len_count[15] = {
79    1,  2,  4,  0,  8,  0, 16,  0, 32,  0,  64,  0, 128,  0, 256,
80};
81
82static VLC rv_dc_lum, rv_dc_chrom;
83
84int ff_rv_decode_dc(MpegEncContext *s, int n)
85{
86    int code;
87
88    if (n < 4) {
89        code = get_vlc2(&s->gb, rv_dc_lum.table, DC_VLC_BITS, 2);
90    } else {
91        code = get_vlc2(&s->gb, rv_dc_chrom.table, DC_VLC_BITS, 2);
92        if (code < 0) {
93            av_log(s->avctx, AV_LOG_ERROR, "chroma dc error\n");
94            return -1;
95        }
96    }
97    return code;
98}
99
100/* read RV 1.0 compatible frame header */
101static int rv10_decode_picture_header(MpegEncContext *s)
102{
103    int mb_count, pb_frame, marker, mb_xy;
104
105    marker = get_bits1(&s->gb);
106
107    if (get_bits1(&s->gb))
108        s->pict_type = AV_PICTURE_TYPE_P;
109    else
110        s->pict_type = AV_PICTURE_TYPE_I;
111
112    if (!marker)
113        av_log(s->avctx, AV_LOG_ERROR, "marker missing\n");
114
115    pb_frame = get_bits1(&s->gb);
116
117    ff_dlog(s->avctx, "pict_type=%d pb_frame=%d\n", s->pict_type, pb_frame);
118
119    if (pb_frame) {
120        avpriv_request_sample(s->avctx, "PB-frame");
121        return AVERROR_PATCHWELCOME;
122    }
123
124    s->qscale = get_bits(&s->gb, 5);
125    if (s->qscale == 0) {
126        av_log(s->avctx, AV_LOG_ERROR, "Invalid qscale value: 0\n");
127        return AVERROR_INVALIDDATA;
128    }
129
130    if (s->pict_type == AV_PICTURE_TYPE_I) {
131        if (s->rv10_version == 3) {
132            /* specific MPEG like DC coding not used */
133            s->last_dc[0] = get_bits(&s->gb, 8);
134            s->last_dc[1] = get_bits(&s->gb, 8);
135            s->last_dc[2] = get_bits(&s->gb, 8);
136            ff_dlog(s->avctx, "DC:%d %d %d\n", s->last_dc[0],
137                    s->last_dc[1], s->last_dc[2]);
138        }
139    }
140    /* if multiple packets per frame are sent, the position at which
141     * to display the macroblocks is coded here */
142
143    mb_xy = s->mb_x + s->mb_y * s->mb_width;
144    if (show_bits(&s->gb, 12) == 0 || (mb_xy && mb_xy < s->mb_num)) {
145        s->mb_x  = get_bits(&s->gb, 6); /* mb_x */
146        s->mb_y  = get_bits(&s->gb, 6); /* mb_y */
147        mb_count = get_bits(&s->gb, 12);
148    } else {
149        s->mb_x  = 0;
150        s->mb_y  = 0;
151        mb_count = s->mb_width * s->mb_height;
152    }
153    skip_bits(&s->gb, 3);   /* ignored */
154    s->f_code          = 1;
155
156    return mb_count;
157}
158
159static int rv20_decode_picture_header(RVDecContext *rv, int whole_size)
160{
161    MpegEncContext *s = &rv->m;
162    int seq, mb_pos, i, ret;
163    int rpr_max;
164
165    i = get_bits(&s->gb, 2);
166    switch (i) {
167    case 0:
168        s->pict_type = AV_PICTURE_TYPE_I;
169        break;
170    case 1:
171        s->pict_type = AV_PICTURE_TYPE_I;
172        break;                                  // hmm ...
173    case 2:
174        s->pict_type = AV_PICTURE_TYPE_P;
175        break;
176    case 3:
177        s->pict_type = AV_PICTURE_TYPE_B;
178        break;
179    default:
180        av_log(s->avctx, AV_LOG_ERROR, "unknown frame type\n");
181        return AVERROR_INVALIDDATA;
182    }
183
184    if (s->low_delay && s->pict_type == AV_PICTURE_TYPE_B) {
185        av_log(s->avctx, AV_LOG_ERROR, "low delay B\n");
186        return -1;
187    }
188    if (!s->last_picture_ptr && s->pict_type == AV_PICTURE_TYPE_B) {
189        av_log(s->avctx, AV_LOG_ERROR, "early B-frame\n");
190        return AVERROR_INVALIDDATA;
191    }
192
193    if (get_bits1(&s->gb)) {
194        av_log(s->avctx, AV_LOG_ERROR, "reserved bit set\n");
195        return AVERROR_INVALIDDATA;
196    }
197
198    s->qscale = get_bits(&s->gb, 5);
199    if (s->qscale == 0) {
200        av_log(s->avctx, AV_LOG_ERROR, "Invalid qscale value: 0\n");
201        return AVERROR_INVALIDDATA;
202    }
203
204    if (RV_GET_MINOR_VER(rv->sub_id) >= 2)
205        s->loop_filter = get_bits1(&s->gb) && !s->avctx->lowres;
206
207    if (RV_GET_MINOR_VER(rv->sub_id) <= 1)
208        seq = get_bits(&s->gb, 8) << 7;
209    else
210        seq = get_bits(&s->gb, 13) << 2;
211
212    rpr_max = s->avctx->extradata[1] & 7;
213    if (rpr_max) {
214        int f, new_w, new_h;
215        int rpr_bits = av_log2(rpr_max) + 1;
216
217        f = get_bits(&s->gb, rpr_bits);
218
219        if (f) {
220            if (s->avctx->extradata_size < 8 + 2 * f) {
221                av_log(s->avctx, AV_LOG_ERROR, "Extradata too small.\n");
222                return AVERROR_INVALIDDATA;
223            }
224
225            new_w = 4 * ((uint8_t *) s->avctx->extradata)[6 + 2 * f];
226            new_h = 4 * ((uint8_t *) s->avctx->extradata)[7 + 2 * f];
227        } else {
228            new_w = rv->orig_width;
229            new_h = rv->orig_height;
230        }
231        if (new_w != s->width || new_h != s->height || !s->context_initialized) {
232            AVRational old_aspect = s->avctx->sample_aspect_ratio;
233            av_log(s->avctx, AV_LOG_DEBUG,
234                   "attempting to change resolution to %dx%d\n", new_w, new_h);
235            if (av_image_check_size(new_w, new_h, 0, s->avctx) < 0)
236                return AVERROR_INVALIDDATA;
237
238            if (whole_size < (new_w + 15)/16 * ((new_h + 15)/16) / 8)
239                return AVERROR_INVALIDDATA;
240
241            ff_mpv_common_end(s);
242
243            // attempt to keep aspect during typical resolution switches
244            if (!old_aspect.num)
245                old_aspect = (AVRational){1, 1};
246            if (2 * (int64_t)new_w * s->height == (int64_t)new_h * s->width)
247                s->avctx->sample_aspect_ratio = av_mul_q(old_aspect, (AVRational){2, 1});
248            if ((int64_t)new_w * s->height == 2 * (int64_t)new_h * s->width)
249                s->avctx->sample_aspect_ratio = av_mul_q(old_aspect, (AVRational){1, 2});
250
251            ret = ff_set_dimensions(s->avctx, new_w, new_h);
252            if (ret < 0)
253                return ret;
254
255            s->width  = new_w;
256            s->height = new_h;
257            if ((ret = ff_mpv_common_init(s)) < 0)
258                return ret;
259        }
260
261        if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
262            av_log(s->avctx, AV_LOG_DEBUG, "F %d/%d/%d\n", f, rpr_bits, rpr_max);
263        }
264    }
265    if (av_image_check_size(s->width, s->height, 0, s->avctx) < 0)
266        return AVERROR_INVALIDDATA;
267
268    mb_pos = ff_h263_decode_mba(s);
269
270    seq |= s->time & ~0x7FFF;
271    if (seq - s->time >  0x4000)
272        seq -= 0x8000;
273    if (seq - s->time < -0x4000)
274        seq += 0x8000;
275
276    if (seq != s->time) {
277        if (s->pict_type != AV_PICTURE_TYPE_B) {
278            s->time            = seq;
279            s->pp_time         = s->time - s->last_non_b_time;
280            s->last_non_b_time = s->time;
281        } else {
282            s->time    = seq;
283            s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
284        }
285    }
286    if (s->pict_type == AV_PICTURE_TYPE_B) {
287        if (s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0) {
288            av_log(s->avctx, AV_LOG_DEBUG,
289                   "messed up order, possible from seeking? skipping current B-frame\n");
290#define ERROR_SKIP_FRAME -123
291            return ERROR_SKIP_FRAME;
292        }
293        ff_mpeg4_init_direct_mv(s);
294    }
295
296    s->no_rounding = get_bits1(&s->gb);
297
298    if (RV_GET_MINOR_VER(rv->sub_id) <= 1 && s->pict_type == AV_PICTURE_TYPE_B)
299        // binary decoder reads 3+2 bits here but they don't seem to be used
300        skip_bits(&s->gb, 5);
301
302    s->f_code          = 1;
303    s->h263_aic        = s->pict_type == AV_PICTURE_TYPE_I;
304    s->modified_quant  = 1;
305    if (!s->avctx->lowres)
306        s->loop_filter = 1;
307
308    if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
309        av_log(s->avctx, AV_LOG_INFO,
310               "num:%5d x:%2d y:%2d type:%d qscale:%2d rnd:%d\n",
311               seq, s->mb_x, s->mb_y, s->pict_type, s->qscale,
312               s->no_rounding);
313    }
314
315    av_assert0(s->pict_type != AV_PICTURE_TYPE_B || !s->low_delay);
316
317    return s->mb_width * s->mb_height - mb_pos;
318}
319
320static av_cold void rv10_build_vlc(VLC *vlc, const uint16_t len_count[15],
321                                   const uint8_t sym_rl[][2], int sym_rl_elems)
322{
323    uint16_t syms[MAX_VLC_ENTRIES];
324    uint8_t  lens[MAX_VLC_ENTRIES];
325    unsigned nb_syms = 0, nb_lens = 0;
326
327    for (unsigned i = 0; i < sym_rl_elems; i++) {
328        unsigned cur_sym = sym_rl[i][0];
329        for (unsigned tmp = nb_syms + sym_rl[i][1]; nb_syms <= tmp; nb_syms++)
330            syms[nb_syms] = 0xFF & cur_sym--;
331    }
332
333    for (unsigned i = 0; i < 15; i++)
334        for (unsigned tmp = nb_lens + len_count[i]; nb_lens < tmp; nb_lens++)
335            lens[nb_lens] = i + 2;
336    av_assert1(nb_lens == nb_syms);
337    ff_init_vlc_from_lengths(vlc, DC_VLC_BITS, nb_lens, lens, 1,
338                             syms, 2, 2, 0, INIT_VLC_STATIC_OVERLONG, NULL);
339}
340
341static av_cold void rv10_init_static(void)
342{
343    static VLCElem table[1472 + 992];
344
345    rv_dc_lum.table             = table;
346    rv_dc_lum.table_allocated   = 1472;
347    rv10_build_vlc(&rv_dc_lum, rv_lum_len_count,
348                   rv_sym_run_len, FF_ARRAY_ELEMS(rv_sym_run_len));
349    for (int i = 0; i < 1 << (DC_VLC_BITS - 7 /* Length of skip prefix */); i++) {
350        /* All codes beginning with 0x7F have the same length and value.
351         * Modifying the table directly saves us the useless subtables. */
352        rv_dc_lum.table[(0x7F << (DC_VLC_BITS - 7)) + i].sym = 255;
353        rv_dc_lum.table[(0x7F << (DC_VLC_BITS - 7)) + i].len = 18;
354    }
355    rv_dc_chrom.table           = &table[1472];
356    rv_dc_chrom.table_allocated = 992;
357    rv10_build_vlc(&rv_dc_chrom, rv_chrom_len_count,
358                   rv_sym_run_len, FF_ARRAY_ELEMS(rv_sym_run_len) - 2);
359    for (int i = 0; i < 1 << (DC_VLC_BITS - 9 /* Length of skip prefix */); i++) {
360        /* Same as above. */
361        rv_dc_chrom.table[(0x1FE << (DC_VLC_BITS - 9)) + i].sym = 255;
362        rv_dc_chrom.table[(0x1FE << (DC_VLC_BITS - 9)) + i].len = 18;
363    }
364    ff_h263_decode_init_vlc();
365}
366
367static av_cold int rv10_decode_init(AVCodecContext *avctx)
368{
369    static AVOnce init_static_once = AV_ONCE_INIT;
370    RVDecContext *rv = avctx->priv_data;
371    MpegEncContext *s = &rv->m;
372    int major_ver, minor_ver, micro_ver, ret;
373
374    if (avctx->extradata_size < 8) {
375        av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");
376        return AVERROR_INVALIDDATA;
377    }
378    if ((ret = av_image_check_size(avctx->coded_width,
379                                   avctx->coded_height, 0, avctx)) < 0)
380        return ret;
381
382    ff_mpv_decode_init(s, avctx);
383
384    s->out_format  = FMT_H263;
385
386    rv->orig_width  =
387    s->width        = avctx->coded_width;
388    rv->orig_height =
389    s->height       = avctx->coded_height;
390
391    s->h263_long_vectors = ((uint8_t *) avctx->extradata)[3] & 1;
392    rv->sub_id           = AV_RB32((uint8_t *) avctx->extradata + 4);
393
394    major_ver = RV_GET_MAJOR_VER(rv->sub_id);
395    minor_ver = RV_GET_MINOR_VER(rv->sub_id);
396    micro_ver = RV_GET_MICRO_VER(rv->sub_id);
397
398    s->low_delay = 1;
399    switch (major_ver) {
400    case 1:
401        s->rv10_version = micro_ver ? 3 : 1;
402        s->obmc         = micro_ver == 2;
403        break;
404    case 2:
405        if (minor_ver >= 2) {
406            s->low_delay           = 0;
407            s->avctx->has_b_frames = 1;
408        }
409        break;
410    default:
411        av_log(s->avctx, AV_LOG_ERROR, "unknown header %X\n", rv->sub_id);
412        avpriv_request_sample(avctx, "RV1/2 version");
413        return AVERROR_PATCHWELCOME;
414    }
415
416    if (avctx->debug & FF_DEBUG_PICT_INFO) {
417        av_log(avctx, AV_LOG_DEBUG, "ver:%X ver0:%"PRIX32"\n", rv->sub_id,
418               ((uint32_t *) avctx->extradata)[0]);
419    }
420
421    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
422
423    ff_mpv_idct_init(s);
424    if ((ret = ff_mpv_common_init(s)) < 0)
425        return ret;
426
427    ff_h263dsp_init(&s->h263dsp);
428
429    /* init static VLCs */
430    ff_thread_once(&init_static_once, rv10_init_static);
431
432    return 0;
433}
434
435static av_cold int rv10_decode_end(AVCodecContext *avctx)
436{
437    MpegEncContext *s = avctx->priv_data;
438
439    ff_mpv_common_end(s);
440    return 0;
441}
442
443static int rv10_decode_packet(AVCodecContext *avctx, const uint8_t *buf,
444                              int buf_size, int buf_size2, int whole_size)
445{
446    RVDecContext *rv = avctx->priv_data;
447    MpegEncContext *s = &rv->m;
448    int mb_count, mb_pos, left, start_mb_x, active_bits_size, ret;
449
450    active_bits_size = buf_size * 8;
451    init_get_bits(&s->gb, buf, FFMAX(buf_size, buf_size2) * 8);
452    if (s->codec_id == AV_CODEC_ID_RV10)
453        mb_count = rv10_decode_picture_header(s);
454    else
455        mb_count = rv20_decode_picture_header(rv, whole_size);
456    if (mb_count < 0) {
457        if (mb_count != ERROR_SKIP_FRAME)
458            av_log(s->avctx, AV_LOG_ERROR, "HEADER ERROR\n");
459        return AVERROR_INVALIDDATA;
460    }
461
462    if (s->mb_x >= s->mb_width ||
463        s->mb_y >= s->mb_height) {
464        av_log(s->avctx, AV_LOG_ERROR, "POS ERROR %d %d\n", s->mb_x, s->mb_y);
465        return AVERROR_INVALIDDATA;
466    }
467    mb_pos = s->mb_y * s->mb_width + s->mb_x;
468    left   = s->mb_width * s->mb_height - mb_pos;
469    if (mb_count > left) {
470        av_log(s->avctx, AV_LOG_ERROR, "COUNT ERROR\n");
471        return AVERROR_INVALIDDATA;
472    }
473
474    if (whole_size < s->mb_width * s->mb_height / 8)
475        return AVERROR_INVALIDDATA;
476
477    if ((s->mb_x == 0 && s->mb_y == 0) || !s->current_picture_ptr) {
478        // FIXME write parser so we always have complete frames?
479        if (s->current_picture_ptr) {
480            ff_er_frame_end(&s->er);
481            ff_mpv_frame_end(s);
482            s->mb_x = s->mb_y = s->resync_mb_x = s->resync_mb_y = 0;
483        }
484        if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
485            return ret;
486        ff_mpeg_er_frame_start(s);
487    } else {
488        if (s->current_picture_ptr->f->pict_type != s->pict_type) {
489            av_log(s->avctx, AV_LOG_ERROR, "Slice type mismatch\n");
490            return AVERROR_INVALIDDATA;
491        }
492    }
493
494
495    ff_dlog(avctx, "qscale=%d\n", s->qscale);
496
497    /* default quantization values */
498    if (s->codec_id == AV_CODEC_ID_RV10) {
499        if (s->mb_y == 0)
500            s->first_slice_line = 1;
501    } else {
502        s->first_slice_line = 1;
503        s->resync_mb_x      = s->mb_x;
504    }
505    start_mb_x     = s->mb_x;
506    s->resync_mb_y = s->mb_y;
507    if (s->h263_aic) {
508        s->y_dc_scale_table =
509        s->c_dc_scale_table = ff_aic_dc_scale_table;
510    } else {
511        s->y_dc_scale_table =
512        s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
513    }
514
515    if (s->modified_quant)
516        s->chroma_qscale_table = ff_h263_chroma_qscale_table;
517
518    ff_set_qscale(s, s->qscale);
519
520    s->rv10_first_dc_coded[0] = 0;
521    s->rv10_first_dc_coded[1] = 0;
522    s->rv10_first_dc_coded[2] = 0;
523    s->block_wrap[0] =
524    s->block_wrap[1] =
525    s->block_wrap[2] =
526    s->block_wrap[3] = s->b8_stride;
527    s->block_wrap[4] =
528    s->block_wrap[5] = s->mb_stride;
529    ff_init_block_index(s);
530
531    /* decode each macroblock */
532    for (s->mb_num_left = mb_count; s->mb_num_left > 0; s->mb_num_left--) {
533        int ret;
534        ff_update_block_index(s);
535        ff_tlog(avctx, "**mb x=%d y=%d\n", s->mb_x, s->mb_y);
536
537        s->mv_dir  = MV_DIR_FORWARD;
538        s->mv_type = MV_TYPE_16X16;
539        ret = ff_h263_decode_mb(s, s->block);
540
541        // Repeat the slice end check from ff_h263_decode_mb with our active
542        // bitstream size
543        if (ret != SLICE_ERROR && active_bits_size >= get_bits_count(&s->gb)) {
544            int v = show_bits(&s->gb, 16);
545
546            if (get_bits_count(&s->gb) + 16 > active_bits_size)
547                v >>= get_bits_count(&s->gb) + 16 - active_bits_size;
548
549            if (!v)
550                ret = SLICE_END;
551        }
552        if (ret != SLICE_ERROR && active_bits_size < get_bits_count(&s->gb) &&
553            8 * buf_size2 >= get_bits_count(&s->gb)) {
554            active_bits_size = buf_size2 * 8;
555            av_log(avctx, AV_LOG_DEBUG, "update size from %d to %d\n",
556                   8 * buf_size, active_bits_size);
557            ret = SLICE_OK;
558        }
559
560        if (ret == SLICE_ERROR || active_bits_size < get_bits_count(&s->gb)) {
561            av_log(s->avctx, AV_LOG_ERROR, "ERROR at MB %d %d\n", s->mb_x,
562                   s->mb_y);
563            return AVERROR_INVALIDDATA;
564        }
565        if (s->pict_type != AV_PICTURE_TYPE_B)
566            ff_h263_update_motion_val(s);
567        ff_mpv_reconstruct_mb(s, s->block);
568        if (s->loop_filter)
569            ff_h263_loop_filter(s);
570
571        if (++s->mb_x == s->mb_width) {
572            s->mb_x = 0;
573            s->mb_y++;
574            ff_init_block_index(s);
575        }
576        if (s->mb_x == s->resync_mb_x)
577            s->first_slice_line = 0;
578        if (ret == SLICE_END)
579            break;
580    }
581
582    ff_er_add_slice(&s->er, start_mb_x, s->resync_mb_y, s->mb_x - 1, s->mb_y,
583                    ER_MB_END);
584
585    return active_bits_size;
586}
587
588static int get_slice_offset(AVCodecContext *avctx, const uint8_t *buf, int n)
589{
590    if (avctx->slice_count)
591        return avctx->slice_offset[n];
592    else
593        return AV_RL32(buf + n * 8);
594}
595
596static int rv10_decode_frame(AVCodecContext *avctx, AVFrame *pict,
597                             int *got_frame, AVPacket *avpkt)
598{
599    const uint8_t *buf = avpkt->data;
600    int buf_size       = avpkt->size;
601    MpegEncContext *s = avctx->priv_data;
602    int i, ret;
603    int slice_count;
604    const uint8_t *slices_hdr = NULL;
605
606    ff_dlog(avctx, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
607
608    /* no supplementary picture */
609    if (buf_size == 0) {
610        return 0;
611    }
612
613    if (!avctx->slice_count) {
614        slice_count = (*buf++) + 1;
615        buf_size--;
616
617        if (!slice_count || buf_size <= 8 * slice_count) {
618            av_log(avctx, AV_LOG_ERROR, "Invalid slice count: %d.\n",
619                   slice_count);
620            return AVERROR_INVALIDDATA;
621        }
622
623        slices_hdr = buf + 4;
624        buf       += 8 * slice_count;
625        buf_size  -= 8 * slice_count;
626    } else
627        slice_count = avctx->slice_count;
628
629    for (i = 0; i < slice_count; i++) {
630        unsigned offset = get_slice_offset(avctx, slices_hdr, i);
631        int size, size2;
632
633        if (offset >= buf_size)
634            return AVERROR_INVALIDDATA;
635
636        if (i + 1 == slice_count)
637            size = buf_size - offset;
638        else
639            size = get_slice_offset(avctx, slices_hdr, i + 1) - offset;
640
641        if (i + 2 >= slice_count)
642            size2 = buf_size - offset;
643        else
644            size2 = get_slice_offset(avctx, slices_hdr, i + 2) - offset;
645
646        if (size <= 0 || size2 <= 0 ||
647            offset + FFMAX(size, size2) > buf_size)
648            return AVERROR_INVALIDDATA;
649
650        if ((ret = rv10_decode_packet(avctx, buf + offset, size, size2, buf_size)) < 0)
651            return ret;
652
653        if (ret > 8 * size)
654            i++;
655    }
656
657    if (s->current_picture_ptr && s->mb_y >= s->mb_height) {
658        ff_er_frame_end(&s->er);
659        ff_mpv_frame_end(s);
660
661        if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
662            if ((ret = av_frame_ref(pict, s->current_picture_ptr->f)) < 0)
663                return ret;
664            ff_print_debug_info(s, s->current_picture_ptr, pict);
665            ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_MPV_QSCALE_TYPE_MPEG1);
666        } else if (s->last_picture_ptr) {
667            if ((ret = av_frame_ref(pict, s->last_picture_ptr->f)) < 0)
668                return ret;
669            ff_print_debug_info(s, s->last_picture_ptr, pict);
670            ff_mpv_export_qp_table(s, pict,s->last_picture_ptr, FF_MPV_QSCALE_TYPE_MPEG1);
671        }
672
673        if (s->last_picture_ptr || s->low_delay) {
674            *got_frame = 1;
675        }
676
677        // so we can detect if frame_end was not called (find some nicer solution...)
678        s->current_picture_ptr = NULL;
679    }
680
681    return avpkt->size;
682}
683
684const FFCodec ff_rv10_decoder = {
685    .p.name         = "rv10",
686    .p.long_name    = NULL_IF_CONFIG_SMALL("RealVideo 1.0"),
687    .p.type         = AVMEDIA_TYPE_VIDEO,
688    .p.id           = AV_CODEC_ID_RV10,
689    .priv_data_size = sizeof(RVDecContext),
690    .init           = rv10_decode_init,
691    .close          = rv10_decode_end,
692    FF_CODEC_DECODE_CB(rv10_decode_frame),
693    .p.capabilities = AV_CODEC_CAP_DR1,
694    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
695    .p.max_lowres   = 3,
696    .p.pix_fmts     = (const enum AVPixelFormat[]) {
697        AV_PIX_FMT_YUV420P,
698        AV_PIX_FMT_NONE
699    },
700};
701
702const FFCodec ff_rv20_decoder = {
703    .p.name         = "rv20",
704    .p.long_name    = NULL_IF_CONFIG_SMALL("RealVideo 2.0"),
705    .p.type         = AVMEDIA_TYPE_VIDEO,
706    .p.id           = AV_CODEC_ID_RV20,
707    .priv_data_size = sizeof(RVDecContext),
708    .init           = rv10_decode_init,
709    .close          = rv10_decode_end,
710    FF_CODEC_DECODE_CB(rv10_decode_frame),
711    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
712    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
713    .flush          = ff_mpeg_flush,
714    .p.max_lowres   = 3,
715    .p.pix_fmts     = (const enum AVPixelFormat[]) {
716        AV_PIX_FMT_YUV420P,
717        AV_PIX_FMT_NONE
718    },
719};
720