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1 /*
2  * Mpeg video formats-related picture management functions
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <stdint.h>
22 
23 #include "libavutil/avassert.h"
24 #include "libavutil/common.h"
25 #include "libavutil/pixdesc.h"
26 #include "libavutil/imgutils.h"
27 
28 #include "avcodec.h"
29 #include "motion_est.h"
30 #include "mpegpicture.h"
31 #include "mpegutils.h"
32 
make_tables_writable(Picture * pic)33 static int make_tables_writable(Picture *pic)
34 {
35     int ret, i;
36 #define MAKE_WRITABLE(table) \
37 do {\
38     if (pic->table &&\
39        (ret = av_buffer_make_writable(&pic->table)) < 0)\
40     return ret;\
41 } while (0)
42 
43     MAKE_WRITABLE(mb_var_buf);
44     MAKE_WRITABLE(mc_mb_var_buf);
45     MAKE_WRITABLE(mb_mean_buf);
46     MAKE_WRITABLE(mbskip_table_buf);
47     MAKE_WRITABLE(qscale_table_buf);
48     MAKE_WRITABLE(mb_type_buf);
49 
50     for (i = 0; i < 2; i++) {
51         MAKE_WRITABLE(motion_val_buf[i]);
52         MAKE_WRITABLE(ref_index_buf[i]);
53     }
54 
55     return 0;
56 }
57 
ff_mpeg_framesize_alloc(AVCodecContext * avctx,MotionEstContext * me,ScratchpadContext * sc,int linesize)58 int ff_mpeg_framesize_alloc(AVCodecContext *avctx, MotionEstContext *me,
59                             ScratchpadContext *sc, int linesize)
60 {
61 #   define EMU_EDGE_HEIGHT (4 * 70)
62     int alloc_size = FFALIGN(FFABS(linesize) + 64, 32);
63 
64     if (avctx->hwaccel)
65         return 0;
66 
67     if (linesize < 24) {
68         av_log(avctx, AV_LOG_ERROR, "Image too small, temporary buffers cannot function\n");
69         return AVERROR_PATCHWELCOME;
70     }
71 
72     if (av_image_check_size2(alloc_size, EMU_EDGE_HEIGHT, avctx->max_pixels, AV_PIX_FMT_NONE, 0, avctx) < 0)
73         return AVERROR(ENOMEM);
74 
75     // edge emu needs blocksize + filter length - 1
76     // (= 17x17 for  halfpel / 21x21 for H.264)
77     // VC-1 computes luma and chroma simultaneously and needs 19X19 + 9x9
78     // at uvlinesize. It supports only YUV420 so 24x24 is enough
79     // linesize * interlaced * MBsize
80     // we also use this buffer for encoding in encode_mb_internal() needig an additional 32 lines
81     if (!FF_ALLOCZ_TYPED_ARRAY(sc->edge_emu_buffer, alloc_size * EMU_EDGE_HEIGHT) ||
82         !FF_ALLOCZ_TYPED_ARRAY(me->scratchpad,      alloc_size * 4 * 16 * 2)) {
83         av_freep(&sc->edge_emu_buffer);
84         return AVERROR(ENOMEM);
85     }
86 
87     me->temp            = me->scratchpad;
88     sc->rd_scratchpad   = me->scratchpad;
89     sc->b_scratchpad    = me->scratchpad;
90     sc->obmc_scratchpad = me->scratchpad + 16;
91 
92     return 0;
93 }
94 
95 /**
96  * Allocate a frame buffer
97  */
alloc_frame_buffer(AVCodecContext * avctx,Picture * pic,MotionEstContext * me,ScratchpadContext * sc,int chroma_x_shift,int chroma_y_shift,int linesize,int uvlinesize)98 static int alloc_frame_buffer(AVCodecContext *avctx,  Picture *pic,
99                               MotionEstContext *me, ScratchpadContext *sc,
100                               int chroma_x_shift, int chroma_y_shift,
101                               int linesize, int uvlinesize)
102 {
103     int edges_needed = av_codec_is_encoder(avctx->codec);
104     int r, ret;
105 
106     pic->tf.f = pic->f;
107     if (avctx->codec_id != AV_CODEC_ID_WMV3IMAGE &&
108         avctx->codec_id != AV_CODEC_ID_VC1IMAGE  &&
109         avctx->codec_id != AV_CODEC_ID_MSS2) {
110         if (edges_needed) {
111             pic->f->width  = avctx->width  + 2 * EDGE_WIDTH;
112             pic->f->height = avctx->height + 2 * EDGE_WIDTH;
113         }
114 
115         r = ff_thread_get_buffer(avctx, &pic->tf,
116                                  pic->reference ? AV_GET_BUFFER_FLAG_REF : 0);
117     } else {
118         pic->f->width  = avctx->width;
119         pic->f->height = avctx->height;
120         pic->f->format = avctx->pix_fmt;
121         r = avcodec_default_get_buffer2(avctx, pic->f, 0);
122     }
123 
124     if (r < 0 || !pic->f->buf[0]) {
125         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed (%d %p)\n",
126                r, pic->f->data[0]);
127         return -1;
128     }
129 
130     if (edges_needed) {
131         int i;
132         for (i = 0; pic->f->data[i]; i++) {
133             int offset = (EDGE_WIDTH >> (i ? chroma_y_shift : 0)) *
134                          pic->f->linesize[i] +
135                          (EDGE_WIDTH >> (i ? chroma_x_shift : 0));
136             pic->f->data[i] += offset;
137         }
138         pic->f->width  = avctx->width;
139         pic->f->height = avctx->height;
140     }
141 
142     if (avctx->hwaccel) {
143         assert(!pic->hwaccel_picture_private);
144         if (avctx->hwaccel->frame_priv_data_size) {
145             pic->hwaccel_priv_buf = av_buffer_allocz(avctx->hwaccel->frame_priv_data_size);
146             if (!pic->hwaccel_priv_buf) {
147                 av_log(avctx, AV_LOG_ERROR, "alloc_frame_buffer() failed (hwaccel private data allocation)\n");
148                 return -1;
149             }
150             pic->hwaccel_picture_private = pic->hwaccel_priv_buf->data;
151         }
152     }
153 
154     if ((linesize   &&   linesize != pic->f->linesize[0]) ||
155         (uvlinesize && uvlinesize != pic->f->linesize[1])) {
156         av_log(avctx, AV_LOG_ERROR,
157                "get_buffer() failed (stride changed: linesize=%d/%d uvlinesize=%d/%d)\n",
158                linesize,   pic->f->linesize[0],
159                uvlinesize, pic->f->linesize[1]);
160         ff_mpeg_unref_picture(avctx, pic);
161         return -1;
162     }
163 
164     if (av_pix_fmt_count_planes(pic->f->format) > 2 &&
165         pic->f->linesize[1] != pic->f->linesize[2]) {
166         av_log(avctx, AV_LOG_ERROR,
167                "get_buffer() failed (uv stride mismatch)\n");
168         ff_mpeg_unref_picture(avctx, pic);
169         return -1;
170     }
171 
172     if (!sc->edge_emu_buffer &&
173         (ret = ff_mpeg_framesize_alloc(avctx, me, sc,
174                                        pic->f->linesize[0])) < 0) {
175         av_log(avctx, AV_LOG_ERROR,
176                "get_buffer() failed to allocate context scratch buffers.\n");
177         ff_mpeg_unref_picture(avctx, pic);
178         return ret;
179     }
180 
181     return 0;
182 }
183 
alloc_picture_tables(AVCodecContext * avctx,Picture * pic,int encoding,int out_format,int mb_stride,int mb_width,int mb_height,int b8_stride)184 static int alloc_picture_tables(AVCodecContext *avctx, Picture *pic, int encoding, int out_format,
185                                 int mb_stride, int mb_width, int mb_height, int b8_stride)
186 {
187     const int big_mb_num    = mb_stride * (mb_height + 1) + 1;
188     const int mb_array_size = mb_stride * mb_height;
189     const int b8_array_size = b8_stride * mb_height * 2;
190     int i;
191 
192 
193     pic->mbskip_table_buf = av_buffer_allocz(mb_array_size + 2);
194     pic->qscale_table_buf = av_buffer_allocz(big_mb_num + mb_stride);
195     pic->mb_type_buf      = av_buffer_allocz((big_mb_num + mb_stride) *
196                                              sizeof(uint32_t));
197     if (!pic->mbskip_table_buf || !pic->qscale_table_buf || !pic->mb_type_buf)
198         return AVERROR(ENOMEM);
199 
200     if (encoding) {
201         pic->mb_var_buf    = av_buffer_allocz(mb_array_size * sizeof(int16_t));
202         pic->mc_mb_var_buf = av_buffer_allocz(mb_array_size * sizeof(int16_t));
203         pic->mb_mean_buf   = av_buffer_allocz(mb_array_size);
204         if (!pic->mb_var_buf || !pic->mc_mb_var_buf || !pic->mb_mean_buf)
205             return AVERROR(ENOMEM);
206     }
207 
208     if (out_format == FMT_H263 || encoding ||
209         (avctx->export_side_data & AV_CODEC_EXPORT_DATA_MVS)) {
210         int mv_size        = 2 * (b8_array_size + 4) * sizeof(int16_t);
211         int ref_index_size = 4 * mb_array_size;
212 
213         for (i = 0; mv_size && i < 2; i++) {
214             pic->motion_val_buf[i] = av_buffer_allocz(mv_size);
215             pic->ref_index_buf[i]  = av_buffer_allocz(ref_index_size);
216             if (!pic->motion_val_buf[i] || !pic->ref_index_buf[i])
217                 return AVERROR(ENOMEM);
218         }
219     }
220 
221     pic->alloc_mb_width  = mb_width;
222     pic->alloc_mb_height = mb_height;
223     pic->alloc_mb_stride = mb_stride;
224 
225     return 0;
226 }
227 
228 /**
229  * Allocate a Picture.
230  * The pixels are allocated/set by calling get_buffer() if shared = 0
231  */
ff_alloc_picture(AVCodecContext * avctx,Picture * pic,MotionEstContext * me,ScratchpadContext * sc,int shared,int encoding,int chroma_x_shift,int chroma_y_shift,int out_format,int mb_stride,int mb_width,int mb_height,int b8_stride,ptrdiff_t * linesize,ptrdiff_t * uvlinesize)232 int ff_alloc_picture(AVCodecContext *avctx, Picture *pic, MotionEstContext *me,
233                      ScratchpadContext *sc, int shared, int encoding,
234                      int chroma_x_shift, int chroma_y_shift, int out_format,
235                      int mb_stride, int mb_width, int mb_height, int b8_stride,
236                      ptrdiff_t *linesize, ptrdiff_t *uvlinesize)
237 {
238     int i, ret;
239 
240     if (pic->qscale_table_buf)
241         if (   pic->alloc_mb_width  != mb_width
242             || pic->alloc_mb_height != mb_height)
243             ff_free_picture_tables(pic);
244 
245     if (shared) {
246         av_assert0(pic->f->data[0]);
247         pic->shared = 1;
248     } else {
249         av_assert0(!pic->f->buf[0]);
250         if (alloc_frame_buffer(avctx, pic, me, sc,
251                                chroma_x_shift, chroma_y_shift,
252                                *linesize, *uvlinesize) < 0)
253             return -1;
254 
255         *linesize   = pic->f->linesize[0];
256         *uvlinesize = pic->f->linesize[1];
257     }
258 
259     if (!pic->qscale_table_buf)
260         ret = alloc_picture_tables(avctx, pic, encoding, out_format,
261                                    mb_stride, mb_width, mb_height, b8_stride);
262     else
263         ret = make_tables_writable(pic);
264     if (ret < 0)
265         goto fail;
266 
267     if (encoding) {
268         pic->mb_var    = (uint16_t*)pic->mb_var_buf->data;
269         pic->mc_mb_var = (uint16_t*)pic->mc_mb_var_buf->data;
270         pic->mb_mean   = pic->mb_mean_buf->data;
271     }
272 
273     pic->mbskip_table = pic->mbskip_table_buf->data;
274     pic->qscale_table = pic->qscale_table_buf->data + 2 * mb_stride + 1;
275     pic->mb_type      = (uint32_t*)pic->mb_type_buf->data + 2 * mb_stride + 1;
276 
277     if (pic->motion_val_buf[0]) {
278         for (i = 0; i < 2; i++) {
279             pic->motion_val[i] = (int16_t (*)[2])pic->motion_val_buf[i]->data + 4;
280             pic->ref_index[i]  = pic->ref_index_buf[i]->data;
281         }
282     }
283 
284     return 0;
285 fail:
286     av_log(avctx, AV_LOG_ERROR, "Error allocating a picture.\n");
287     ff_mpeg_unref_picture(avctx, pic);
288     ff_free_picture_tables(pic);
289     return AVERROR(ENOMEM);
290 }
291 
292 /**
293  * Deallocate a picture.
294  */
ff_mpeg_unref_picture(AVCodecContext * avctx,Picture * pic)295 void ff_mpeg_unref_picture(AVCodecContext *avctx, Picture *pic)
296 {
297     int off = offsetof(Picture, mb_mean) + sizeof(pic->mb_mean);
298 
299     pic->tf.f = pic->f;
300     /* WM Image / Screen codecs allocate internal buffers with different
301      * dimensions / colorspaces; ignore user-defined callbacks for these. */
302     if (avctx->codec_id != AV_CODEC_ID_WMV3IMAGE &&
303         avctx->codec_id != AV_CODEC_ID_VC1IMAGE  &&
304         avctx->codec_id != AV_CODEC_ID_MSS2)
305         ff_thread_release_buffer(avctx, &pic->tf);
306     else if (pic->f)
307         av_frame_unref(pic->f);
308 
309     av_buffer_unref(&pic->hwaccel_priv_buf);
310 
311     if (pic->needs_realloc)
312         ff_free_picture_tables(pic);
313 
314     memset((uint8_t*)pic + off, 0, sizeof(*pic) - off);
315 }
316 
ff_update_picture_tables(Picture * dst,Picture * src)317 int ff_update_picture_tables(Picture *dst, Picture *src)
318 {
319     int i, ret;
320 
321     ret  = av_buffer_replace(&dst->mb_var_buf,       src->mb_var_buf);
322     ret |= av_buffer_replace(&dst->mc_mb_var_buf,    src->mc_mb_var_buf);
323     ret |= av_buffer_replace(&dst->mb_mean_buf,      src->mb_mean_buf);
324     ret |= av_buffer_replace(&dst->mbskip_table_buf, src->mbskip_table_buf);
325     ret |= av_buffer_replace(&dst->qscale_table_buf, src->qscale_table_buf);
326     ret |= av_buffer_replace(&dst->mb_type_buf,      src->mb_type_buf);
327     for (i = 0; i < 2; i++) {
328         ret |= av_buffer_replace(&dst->motion_val_buf[i], src->motion_val_buf[i]);
329         ret |= av_buffer_replace(&dst->ref_index_buf[i],  src->ref_index_buf[i]);
330     }
331 
332     if (ret < 0) {
333         ff_free_picture_tables(dst);
334         return ret;
335     }
336 
337     dst->mb_var        = src->mb_var;
338     dst->mc_mb_var     = src->mc_mb_var;
339     dst->mb_mean       = src->mb_mean;
340     dst->mbskip_table  = src->mbskip_table;
341     dst->qscale_table  = src->qscale_table;
342     dst->mb_type       = src->mb_type;
343     for (i = 0; i < 2; i++) {
344         dst->motion_val[i] = src->motion_val[i];
345         dst->ref_index[i]  = src->ref_index[i];
346     }
347 
348     dst->alloc_mb_width  = src->alloc_mb_width;
349     dst->alloc_mb_height = src->alloc_mb_height;
350     dst->alloc_mb_stride = src->alloc_mb_stride;
351 
352     return 0;
353 }
354 
ff_mpeg_ref_picture(AVCodecContext * avctx,Picture * dst,Picture * src)355 int ff_mpeg_ref_picture(AVCodecContext *avctx, Picture *dst, Picture *src)
356 {
357     int ret;
358 
359     av_assert0(!dst->f->buf[0]);
360     av_assert0(src->f->buf[0]);
361 
362     src->tf.f = src->f;
363     dst->tf.f = dst->f;
364     ret = ff_thread_ref_frame(&dst->tf, &src->tf);
365     if (ret < 0)
366         goto fail;
367 
368     ret = ff_update_picture_tables(dst, src);
369     if (ret < 0)
370         goto fail;
371 
372     if (src->hwaccel_picture_private) {
373         dst->hwaccel_priv_buf = av_buffer_ref(src->hwaccel_priv_buf);
374         if (!dst->hwaccel_priv_buf) {
375             ret = AVERROR(ENOMEM);
376             goto fail;
377         }
378         dst->hwaccel_picture_private = dst->hwaccel_priv_buf->data;
379     }
380 
381     dst->field_picture           = src->field_picture;
382     dst->mb_var_sum              = src->mb_var_sum;
383     dst->mc_mb_var_sum           = src->mc_mb_var_sum;
384     dst->b_frame_score           = src->b_frame_score;
385     dst->needs_realloc           = src->needs_realloc;
386     dst->reference               = src->reference;
387     dst->shared                  = src->shared;
388 
389     memcpy(dst->encoding_error, src->encoding_error,
390            sizeof(dst->encoding_error));
391 
392     return 0;
393 fail:
394     ff_mpeg_unref_picture(avctx, dst);
395     return ret;
396 }
397 
pic_is_unused(Picture * pic)398 static inline int pic_is_unused(Picture *pic)
399 {
400     if (!pic->f->buf[0])
401         return 1;
402     if (pic->needs_realloc && !(pic->reference & DELAYED_PIC_REF))
403         return 1;
404     return 0;
405 }
406 
find_unused_picture(AVCodecContext * avctx,Picture * picture,int shared)407 static int find_unused_picture(AVCodecContext *avctx, Picture *picture, int shared)
408 {
409     int i;
410 
411     if (shared) {
412         for (i = 0; i < MAX_PICTURE_COUNT; i++) {
413             if (!picture[i].f->buf[0])
414                 return i;
415         }
416     } else {
417         for (i = 0; i < MAX_PICTURE_COUNT; i++) {
418             if (pic_is_unused(&picture[i]))
419                 return i;
420         }
421     }
422 
423     av_log(avctx, AV_LOG_FATAL,
424            "Internal error, picture buffer overflow\n");
425     /* We could return -1, but the codec would crash trying to draw into a
426      * non-existing frame anyway. This is safer than waiting for a random crash.
427      * Also the return of this is never useful, an encoder must only allocate
428      * as much as allowed in the specification. This has no relationship to how
429      * much libavcodec could allocate (and MAX_PICTURE_COUNT is always large
430      * enough for such valid streams).
431      * Plus, a decoder has to check stream validity and remove frames if too
432      * many reference frames are around. Waiting for "OOM" is not correct at
433      * all. Similarly, missing reference frames have to be replaced by
434      * interpolated/MC frames, anything else is a bug in the codec ...
435      */
436     abort();
437     return -1;
438 }
439 
ff_find_unused_picture(AVCodecContext * avctx,Picture * picture,int shared)440 int ff_find_unused_picture(AVCodecContext *avctx, Picture *picture, int shared)
441 {
442     int ret = find_unused_picture(avctx, picture, shared);
443 
444     if (ret >= 0 && ret < MAX_PICTURE_COUNT) {
445         if (picture[ret].needs_realloc) {
446             picture[ret].needs_realloc = 0;
447             ff_free_picture_tables(&picture[ret]);
448             ff_mpeg_unref_picture(avctx, &picture[ret]);
449         }
450     }
451     return ret;
452 }
453 
ff_free_picture_tables(Picture * pic)454 void ff_free_picture_tables(Picture *pic)
455 {
456     int i;
457 
458     pic->alloc_mb_width  =
459     pic->alloc_mb_height = 0;
460 
461     av_buffer_unref(&pic->mb_var_buf);
462     av_buffer_unref(&pic->mc_mb_var_buf);
463     av_buffer_unref(&pic->mb_mean_buf);
464     av_buffer_unref(&pic->mbskip_table_buf);
465     av_buffer_unref(&pic->qscale_table_buf);
466     av_buffer_unref(&pic->mb_type_buf);
467 
468     for (i = 0; i < 2; i++) {
469         av_buffer_unref(&pic->motion_val_buf[i]);
470         av_buffer_unref(&pic->ref_index_buf[i]);
471     }
472 }
473