libavfilter/formats: Fix parsing of channel specifications with a trailing 'c'.
[ffmpeg.git] / libavfilter / formats.c
1 /*
2  * Filter layer - format negotiation
3  * Copyright (c) 2007 Bobby Bingham
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 #include "libavutil/avassert.h"
23 #include "libavutil/channel_layout.h"
24 #include "libavutil/common.h"
25 #include "libavutil/eval.h"
26 #include "libavutil/pixdesc.h"
27 #include "libavutil/parseutils.h"
28 #include "avfilter.h"
29 #include "internal.h"
30 #include "formats.h"
31
32 #define KNOWN(l) (!FF_LAYOUT2COUNT(l)) /* for readability */
33
34 /**
35  * Add all refs from a to ret and destroy a.
36  */
37 #define MERGE_REF(ret, a, fmts, type, fail)                                \
38 do {                                                                       \
39     type ***tmp;                                                           \
40     int i;                                                                 \
41                                                                            \
42     if (!(tmp = av_realloc_array(ret->refs, ret->refcount + a->refcount,   \
43                                  sizeof(*tmp))))                           \
44         goto fail;                                                         \
45     ret->refs = tmp;                                                       \
46                                                                            \
47     for (i = 0; i < a->refcount; i ++) {                                   \
48         ret->refs[ret->refcount] = a->refs[i];                             \
49         *ret->refs[ret->refcount++] = ret;                                 \
50     }                                                                      \
51                                                                            \
52     av_freep(&a->refs);                                                    \
53     av_freep(&a->fmts);                                                    \
54     av_freep(&a);                                                          \
55 } while (0)
56
57 /**
58  * Add all formats common for a and b to ret, copy the refs and destroy
59  * a and b.
60  */
61 #define MERGE_FORMATS(ret, a, b, fmts, nb, type, fail)                          \
62 do {                                                                            \
63     int i, j, k = 0, count = FFMIN(a->nb, b->nb);                               \
64                                                                                 \
65     if (!(ret = av_mallocz(sizeof(*ret))))                                      \
66         goto fail;                                                              \
67                                                                                 \
68     if (count) {                                                                \
69         if (!(ret->fmts = av_malloc_array(count, sizeof(*ret->fmts))))          \
70             goto fail;                                                          \
71         for (i = 0; i < a->nb; i++)                                             \
72             for (j = 0; j < b->nb; j++)                                         \
73                 if (a->fmts[i] == b->fmts[j]) {                                 \
74                     if(k >= FFMIN(a->nb, b->nb)){                               \
75                         av_log(NULL, AV_LOG_ERROR, "Duplicate formats in avfilter_merge_formats() detected\n"); \
76                         av_free(ret->fmts);                                     \
77                         av_free(ret);                                           \
78                         return NULL;                                            \
79                     }                                                           \
80                     ret->fmts[k++] = a->fmts[i];                                \
81                 }                                                               \
82     }                                                                           \
83     ret->nb = k;                                                                \
84     /* check that there was at least one common format */                       \
85     if (!ret->nb)                                                               \
86         goto fail;                                                              \
87                                                                                 \
88     MERGE_REF(ret, a, fmts, type, fail);                                        \
89     MERGE_REF(ret, b, fmts, type, fail);                                        \
90 } while (0)
91
92 AVFilterFormats *ff_merge_formats(AVFilterFormats *a, AVFilterFormats *b,
93                                   enum AVMediaType type)
94 {
95     AVFilterFormats *ret = NULL;
96     int i, j;
97     int alpha1=0, alpha2=0;
98     int chroma1=0, chroma2=0;
99
100     if (a == b)
101         return a;
102
103     /* Do not lose chroma or alpha in merging.
104        It happens if both lists have formats with chroma (resp. alpha), but
105        the only formats in common do not have it (e.g. YUV+gray vs.
106        RGB+gray): in that case, the merging would select the gray format,
107        possibly causing a lossy conversion elsewhere in the graph.
108        To avoid that, pretend that there are no common formats to force the
109        insertion of a conversion filter. */
110     if (type == AVMEDIA_TYPE_VIDEO)
111         for (i = 0; i < a->nb_formats; i++)
112             for (j = 0; j < b->nb_formats; j++) {
113                 const AVPixFmtDescriptor *adesc = av_pix_fmt_desc_get(a->formats[i]);
114                 const AVPixFmtDescriptor *bdesc = av_pix_fmt_desc_get(b->formats[j]);
115                 alpha2 |= adesc->flags & bdesc->flags & AV_PIX_FMT_FLAG_ALPHA;
116                 chroma2|= adesc->nb_components > 1 && bdesc->nb_components > 1;
117                 if (a->formats[i] == b->formats[j]) {
118                     alpha1 |= adesc->flags & AV_PIX_FMT_FLAG_ALPHA;
119                     chroma1|= adesc->nb_components > 1;
120                 }
121             }
122
123     // If chroma or alpha can be lost through merging then do not merge
124     if (alpha2 > alpha1 || chroma2 > chroma1)
125         return NULL;
126
127     MERGE_FORMATS(ret, a, b, formats, nb_formats, AVFilterFormats, fail);
128
129     return ret;
130 fail:
131     if (ret) {
132         av_freep(&ret->refs);
133         av_freep(&ret->formats);
134     }
135     av_freep(&ret);
136     return NULL;
137 }
138
139 AVFilterFormats *ff_merge_samplerates(AVFilterFormats *a,
140                                       AVFilterFormats *b)
141 {
142     AVFilterFormats *ret = NULL;
143
144     if (a == b) return a;
145
146     if (a->nb_formats && b->nb_formats) {
147         MERGE_FORMATS(ret, a, b, formats, nb_formats, AVFilterFormats, fail);
148     } else if (a->nb_formats) {
149         MERGE_REF(a, b, formats, AVFilterFormats, fail);
150         ret = a;
151     } else {
152         MERGE_REF(b, a, formats, AVFilterFormats, fail);
153         ret = b;
154     }
155
156     return ret;
157 fail:
158     if (ret) {
159         av_freep(&ret->refs);
160         av_freep(&ret->formats);
161     }
162     av_freep(&ret);
163     return NULL;
164 }
165
166 AVFilterChannelLayouts *ff_merge_channel_layouts(AVFilterChannelLayouts *a,
167                                                  AVFilterChannelLayouts *b)
168 {
169     AVFilterChannelLayouts *ret = NULL;
170     unsigned a_all = a->all_layouts + a->all_counts;
171     unsigned b_all = b->all_layouts + b->all_counts;
172     int ret_max, ret_nb = 0, i, j, round;
173
174     if (a == b) return a;
175
176     /* Put the most generic set in a, to avoid doing everything twice */
177     if (a_all < b_all) {
178         FFSWAP(AVFilterChannelLayouts *, a, b);
179         FFSWAP(unsigned, a_all, b_all);
180     }
181     if (a_all) {
182         if (a_all == 1 && !b_all) {
183             /* keep only known layouts in b; works also for b_all = 1 */
184             for (i = j = 0; i < b->nb_channel_layouts; i++)
185                 if (KNOWN(b->channel_layouts[i]))
186                     b->channel_layouts[j++] = b->channel_layouts[i];
187             /* Not optimal: the unknown layouts of b may become known after
188                another merge. */
189             if (!j)
190                 return NULL;
191             b->nb_channel_layouts = j;
192         }
193         MERGE_REF(b, a, channel_layouts, AVFilterChannelLayouts, fail);
194         return b;
195     }
196
197     ret_max = a->nb_channel_layouts + b->nb_channel_layouts;
198     if (!(ret = av_mallocz(sizeof(*ret))) ||
199         !(ret->channel_layouts = av_malloc_array(ret_max,
200                                                  sizeof(*ret->channel_layouts))))
201         goto fail;
202
203     /* a[known] intersect b[known] */
204     for (i = 0; i < a->nb_channel_layouts; i++) {
205         if (!KNOWN(a->channel_layouts[i]))
206             continue;
207         for (j = 0; j < b->nb_channel_layouts; j++) {
208             if (a->channel_layouts[i] == b->channel_layouts[j]) {
209                 ret->channel_layouts[ret_nb++] = a->channel_layouts[i];
210                 a->channel_layouts[i] = b->channel_layouts[j] = 0;
211             }
212         }
213     }
214     /* 1st round: a[known] intersect b[generic]
215        2nd round: a[generic] intersect b[known] */
216     for (round = 0; round < 2; round++) {
217         for (i = 0; i < a->nb_channel_layouts; i++) {
218             uint64_t fmt = a->channel_layouts[i], bfmt;
219             if (!fmt || !KNOWN(fmt))
220                 continue;
221             bfmt = FF_COUNT2LAYOUT(av_get_channel_layout_nb_channels(fmt));
222             for (j = 0; j < b->nb_channel_layouts; j++)
223                 if (b->channel_layouts[j] == bfmt)
224                     ret->channel_layouts[ret_nb++] = a->channel_layouts[i];
225         }
226         /* 1st round: swap to prepare 2nd round; 2nd round: put it back */
227         FFSWAP(AVFilterChannelLayouts *, a, b);
228     }
229     /* a[generic] intersect b[generic] */
230     for (i = 0; i < a->nb_channel_layouts; i++) {
231         if (KNOWN(a->channel_layouts[i]))
232             continue;
233         for (j = 0; j < b->nb_channel_layouts; j++)
234             if (a->channel_layouts[i] == b->channel_layouts[j])
235                 ret->channel_layouts[ret_nb++] = a->channel_layouts[i];
236     }
237
238     ret->nb_channel_layouts = ret_nb;
239     if (!ret->nb_channel_layouts)
240         goto fail;
241     MERGE_REF(ret, a, channel_layouts, AVFilterChannelLayouts, fail);
242     MERGE_REF(ret, b, channel_layouts, AVFilterChannelLayouts, fail);
243     return ret;
244
245 fail:
246     if (ret) {
247         av_freep(&ret->refs);
248         av_freep(&ret->channel_layouts);
249     }
250     av_freep(&ret);
251     return NULL;
252 }
253
254 int ff_fmt_is_in(int fmt, const int *fmts)
255 {
256     const int *p;
257
258     for (p = fmts; *p != -1; p++) {
259         if (fmt == *p)
260             return 1;
261     }
262     return 0;
263 }
264
265 #define MAKE_FORMAT_LIST(type, field, count_field)                      \
266     type *formats;                                                      \
267     int count = 0;                                                      \
268     if (fmts)                                                           \
269         for (count = 0; fmts[count] != -1; count++)                     \
270             ;                                                           \
271     formats = av_mallocz(sizeof(*formats));                             \
272     if (!formats)                                                       \
273         return NULL;                                                    \
274     formats->count_field = count;                                       \
275     if (count) {                                                        \
276         formats->field = av_malloc_array(count, sizeof(*formats->field));      \
277         if (!formats->field) {                                          \
278             av_freep(&formats);                                         \
279             return NULL;                                                \
280         }                                                               \
281     }
282
283 AVFilterFormats *ff_make_format_list(const int *fmts)
284 {
285     MAKE_FORMAT_LIST(AVFilterFormats, formats, nb_formats);
286     while (count--)
287         formats->formats[count] = fmts[count];
288
289     return formats;
290 }
291
292 AVFilterChannelLayouts *avfilter_make_format64_list(const int64_t *fmts)
293 {
294     MAKE_FORMAT_LIST(AVFilterChannelLayouts,
295                      channel_layouts, nb_channel_layouts);
296     if (count)
297         memcpy(formats->channel_layouts, fmts,
298                sizeof(*formats->channel_layouts) * count);
299
300     return formats;
301 }
302
303 #define ADD_FORMAT(f, fmt, type, list, nb)                  \
304 do {                                                        \
305     type *fmts;                                             \
306     void *oldf = *f;                                        \
307                                                             \
308     if (!(*f) && !(*f = av_mallocz(sizeof(**f))))           \
309         return AVERROR(ENOMEM);                             \
310                                                             \
311     fmts = av_realloc_array((*f)->list, (*f)->nb + 1,       \
312                             sizeof(*(*f)->list));           \
313     if (!fmts) {                                            \
314         if (!oldf)                                          \
315             av_freep(f);                                    \
316         return AVERROR(ENOMEM);                             \
317     }                                                       \
318                                                             \
319     (*f)->list = fmts;                                      \
320     (*f)->list[(*f)->nb++] = fmt;                           \
321 } while (0)
322
323 int ff_add_format(AVFilterFormats **avff, int64_t fmt)
324 {
325     ADD_FORMAT(avff, fmt, int, formats, nb_formats);
326     return 0;
327 }
328
329 int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout)
330 {
331     av_assert1(!(*l && (*l)->all_layouts));
332     ADD_FORMAT(l, channel_layout, uint64_t, channel_layouts, nb_channel_layouts);
333     return 0;
334 }
335
336 AVFilterFormats *ff_all_formats(enum AVMediaType type)
337 {
338     AVFilterFormats *ret = NULL;
339
340     if (type == AVMEDIA_TYPE_VIDEO) {
341         const AVPixFmtDescriptor *desc = NULL;
342         while ((desc = av_pix_fmt_desc_next(desc))) {
343             if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL))
344                 ff_add_format(&ret, av_pix_fmt_desc_get_id(desc));
345         }
346     } else if (type == AVMEDIA_TYPE_AUDIO) {
347         enum AVSampleFormat fmt = 0;
348         while (av_get_sample_fmt_name(fmt)) {
349             ff_add_format(&ret, fmt);
350             fmt++;
351         }
352     }
353
354     return ret;
355 }
356
357 const int64_t avfilter_all_channel_layouts[] = {
358 #include "all_channel_layouts.inc"
359     -1
360 };
361
362 // AVFilterFormats *avfilter_make_all_channel_layouts(void)
363 // {
364 //     return avfilter_make_format64_list(avfilter_all_channel_layouts);
365 // }
366
367 AVFilterFormats *ff_planar_sample_fmts(void)
368 {
369     AVFilterFormats *ret = NULL;
370     int fmt;
371
372     for (fmt = 0; av_get_bytes_per_sample(fmt)>0; fmt++)
373         if (av_sample_fmt_is_planar(fmt))
374             ff_add_format(&ret, fmt);
375
376     return ret;
377 }
378
379 AVFilterFormats *ff_all_samplerates(void)
380 {
381     AVFilterFormats *ret = av_mallocz(sizeof(*ret));
382     return ret;
383 }
384
385 AVFilterChannelLayouts *ff_all_channel_layouts(void)
386 {
387     AVFilterChannelLayouts *ret = av_mallocz(sizeof(*ret));
388     if (!ret)
389         return NULL;
390     ret->all_layouts = 1;
391     return ret;
392 }
393
394 AVFilterChannelLayouts *ff_all_channel_counts(void)
395 {
396     AVFilterChannelLayouts *ret = av_mallocz(sizeof(*ret));
397     if (!ret)
398         return NULL;
399     ret->all_layouts = ret->all_counts = 1;
400     return ret;
401 }
402
403 #define FORMATS_REF(f, ref)                                                     \
404     void *tmp;                                                                  \
405                                                                                 \
406     if (!ref)                                                                   \
407         return AVERROR_BUG;                                                     \
408                                                                                 \
409     tmp = av_realloc_array(f->refs, sizeof(*f->refs), f->refcount + 1);         \
410     if (!tmp)                                                                   \
411         return AVERROR(ENOMEM);                                                 \
412     f->refs = tmp;                                                              \
413     f->refs[f->refcount++] = ref;                                               \
414     *ref = f;                                                                   \
415     return 0
416
417 int ff_channel_layouts_ref(AVFilterChannelLayouts *f, AVFilterChannelLayouts **ref)
418 {
419     FORMATS_REF(f, ref);
420 }
421
422 int ff_formats_ref(AVFilterFormats *f, AVFilterFormats **ref)
423 {
424     FORMATS_REF(f, ref);
425 }
426
427 #define FIND_REF_INDEX(ref, idx)            \
428 do {                                        \
429     int i;                                  \
430     for (i = 0; i < (*ref)->refcount; i ++) \
431         if((*ref)->refs[i] == ref) {        \
432             idx = i;                        \
433             break;                          \
434         }                                   \
435 } while (0)
436
437 #define FORMATS_UNREF(ref, list)                                   \
438 do {                                                               \
439     int idx = -1;                                                  \
440                                                                    \
441     if (!*ref)                                                     \
442         return;                                                    \
443                                                                    \
444     FIND_REF_INDEX(ref, idx);                                      \
445                                                                    \
446     if (idx >= 0)                                                  \
447         memmove((*ref)->refs + idx, (*ref)->refs + idx + 1,        \
448             sizeof(*(*ref)->refs) * ((*ref)->refcount - idx - 1)); \
449                                                                    \
450     if(!--(*ref)->refcount) {                                      \
451         av_free((*ref)->list);                                     \
452         av_free((*ref)->refs);                                     \
453         av_free(*ref);                                             \
454     }                                                              \
455     *ref = NULL;                                                   \
456 } while (0)
457
458 void ff_formats_unref(AVFilterFormats **ref)
459 {
460     FORMATS_UNREF(ref, formats);
461 }
462
463 void ff_channel_layouts_unref(AVFilterChannelLayouts **ref)
464 {
465     FORMATS_UNREF(ref, channel_layouts);
466 }
467
468 #define FORMATS_CHANGEREF(oldref, newref)       \
469 do {                                            \
470     int idx = -1;                               \
471                                                 \
472     FIND_REF_INDEX(oldref, idx);                \
473                                                 \
474     if (idx >= 0) {                             \
475         (*oldref)->refs[idx] = newref;          \
476         *newref = *oldref;                      \
477         *oldref = NULL;                         \
478     }                                           \
479 } while (0)
480
481 void ff_channel_layouts_changeref(AVFilterChannelLayouts **oldref,
482                                   AVFilterChannelLayouts **newref)
483 {
484     FORMATS_CHANGEREF(oldref, newref);
485 }
486
487 void ff_formats_changeref(AVFilterFormats **oldref, AVFilterFormats **newref)
488 {
489     FORMATS_CHANGEREF(oldref, newref);
490 }
491
492 #define SET_COMMON_FORMATS(ctx, fmts, in_fmts, out_fmts, ref, list) \
493     int count = 0, i;                                               \
494                                                                     \
495     if (!fmts)                                                      \
496         return AVERROR_BUG;                                         \
497                                                                     \
498     for (i = 0; i < ctx->nb_inputs; i++) {                          \
499         if (ctx->inputs[i] && !ctx->inputs[i]->out_fmts) {          \
500             int ret = ref(fmts, &ctx->inputs[i]->out_fmts);         \
501             if (ret < 0)                                            \
502                 return ret;                                         \
503             count++;                                                \
504         }                                                           \
505     }                                                               \
506     for (i = 0; i < ctx->nb_outputs; i++) {                         \
507         if (ctx->outputs[i] && !ctx->outputs[i]->in_fmts) {         \
508             int ret = ref(fmts, &ctx->outputs[i]->in_fmts);         \
509             if (ret < 0)                                            \
510                 return ret;                                         \
511             count++;                                                \
512         }                                                           \
513     }                                                               \
514                                                                     \
515     if (!count) {                                                   \
516         av_freep(&fmts->list);                                      \
517         av_freep(&fmts->refs);                                      \
518         av_freep(&fmts);                                            \
519     }                                                               \
520                                                                     \
521     return 0;
522
523 int ff_set_common_channel_layouts(AVFilterContext *ctx,
524                                   AVFilterChannelLayouts *layouts)
525 {
526     SET_COMMON_FORMATS(ctx, layouts, in_channel_layouts, out_channel_layouts,
527                        ff_channel_layouts_ref, channel_layouts);
528 }
529
530 int ff_set_common_samplerates(AVFilterContext *ctx,
531                               AVFilterFormats *samplerates)
532 {
533     SET_COMMON_FORMATS(ctx, samplerates, in_samplerates, out_samplerates,
534                        ff_formats_ref, formats);
535 }
536
537 /**
538  * A helper for query_formats() which sets all links to the same list of
539  * formats. If there are no links hooked to this filter, the list of formats is
540  * freed.
541  */
542 int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
543 {
544     SET_COMMON_FORMATS(ctx, formats, in_formats, out_formats,
545                        ff_formats_ref, formats);
546 }
547
548 static int default_query_formats_common(AVFilterContext *ctx,
549                                         AVFilterChannelLayouts *(layouts)(void))
550 {
551     int ret;
552     enum AVMediaType type = ctx->inputs  && ctx->inputs [0] ? ctx->inputs [0]->type :
553                             ctx->outputs && ctx->outputs[0] ? ctx->outputs[0]->type :
554                             AVMEDIA_TYPE_VIDEO;
555
556     ret = ff_set_common_formats(ctx, ff_all_formats(type));
557     if (ret < 0)
558         return ret;
559     if (type == AVMEDIA_TYPE_AUDIO) {
560         ret = ff_set_common_channel_layouts(ctx, layouts());
561         if (ret < 0)
562             return ret;
563         ret = ff_set_common_samplerates(ctx, ff_all_samplerates());
564         if (ret < 0)
565             return ret;
566     }
567
568     return 0;
569 }
570
571 int ff_default_query_formats(AVFilterContext *ctx)
572 {
573     return default_query_formats_common(ctx, ff_all_channel_layouts);
574 }
575
576 int ff_query_formats_all(AVFilterContext *ctx)
577 {
578     return default_query_formats_common(ctx, ff_all_channel_counts);
579 }
580
581 /* internal functions for parsing audio format arguments */
582
583 int ff_parse_pixel_format(enum AVPixelFormat *ret, const char *arg, void *log_ctx)
584 {
585     char *tail;
586     int pix_fmt = av_get_pix_fmt(arg);
587     if (pix_fmt == AV_PIX_FMT_NONE) {
588         pix_fmt = strtol(arg, &tail, 0);
589         if (*tail || !av_pix_fmt_desc_get(pix_fmt)) {
590             av_log(log_ctx, AV_LOG_ERROR, "Invalid pixel format '%s'\n", arg);
591             return AVERROR(EINVAL);
592         }
593     }
594     *ret = pix_fmt;
595     return 0;
596 }
597
598 int ff_parse_sample_format(int *ret, const char *arg, void *log_ctx)
599 {
600     char *tail;
601     int sfmt = av_get_sample_fmt(arg);
602     if (sfmt == AV_SAMPLE_FMT_NONE) {
603         sfmt = strtol(arg, &tail, 0);
604         if (*tail || av_get_bytes_per_sample(sfmt)<=0) {
605             av_log(log_ctx, AV_LOG_ERROR, "Invalid sample format '%s'\n", arg);
606             return AVERROR(EINVAL);
607         }
608     }
609     *ret = sfmt;
610     return 0;
611 }
612
613 int ff_parse_time_base(AVRational *ret, const char *arg, void *log_ctx)
614 {
615     AVRational r;
616     if(av_parse_ratio(&r, arg, INT_MAX, 0, log_ctx) < 0 ||r.num<=0  ||r.den<=0) {
617         av_log(log_ctx, AV_LOG_ERROR, "Invalid time base '%s'\n", arg);
618         return AVERROR(EINVAL);
619     }
620     *ret = r;
621     return 0;
622 }
623
624 int ff_parse_sample_rate(int *ret, const char *arg, void *log_ctx)
625 {
626     char *tail;
627     double srate = av_strtod(arg, &tail);
628     if (*tail || srate < 1 || (int)srate != srate || srate > INT_MAX) {
629         av_log(log_ctx, AV_LOG_ERROR, "Invalid sample rate '%s'\n", arg);
630         return AVERROR(EINVAL);
631     }
632     *ret = srate;
633     return 0;
634 }
635
636 int ff_parse_channel_layout(int64_t *ret, int *nret, const char *arg,
637                             void *log_ctx)
638 {
639     char *tail;
640     int64_t chlayout;
641
642     chlayout = av_get_channel_layout(arg);
643     if (chlayout == 0) {
644         chlayout = strtol(arg, &tail, 10);
645         if (!(*tail == '\0' || *tail == 'c' && *(tail + 1) == '\0') || chlayout <= 0 || chlayout > 63) {
646             av_log(log_ctx, AV_LOG_ERROR, "Invalid channel layout '%s'\n", arg);
647             return AVERROR(EINVAL);
648         }
649         if (nret) {
650             *nret = chlayout;
651             *ret = 0;
652             return 0;
653         }
654     }
655     *ret = chlayout;
656     if (nret)
657         *nret = av_get_channel_layout_nb_channels(chlayout);
658     return 0;
659 }
660
661 #ifdef TEST
662
663 #undef printf
664
665 int main(void)
666 {
667     const int64_t *cl;
668     char buf[512];
669     int i;
670     const char *teststrings[] ={
671         "blah",
672         "1",
673         "2",
674         "-1",
675         "60",
676         "65",
677         "1c",
678         "2c",
679         "-1c",
680         "60c",
681         "65c",
682         "5.1",
683         "stereo",
684         "1+1+1+1",
685         "1c+1c+1c+1c",
686         "2c+1c",
687         "0x3",
688     };
689
690     for (cl = avfilter_all_channel_layouts; *cl != -1; cl++) {
691         av_get_channel_layout_string(buf, sizeof(buf), -1, *cl);
692         printf("%s\n", buf);
693     }
694
695     for ( i = 0; i<FF_ARRAY_ELEMS(teststrings); i++) {
696         int64_t layout = -1;
697         int count = -1;
698         int ret;
699         ret = ff_parse_channel_layout(&layout, &count, teststrings[i], NULL);
700
701         printf ("%d = ff_parse_channel_layout(%016"PRIX64", %2d, %s);\n", ret ? -1 : 0, layout, count, teststrings[i]);
702     }
703
704     return 0;
705 }
706
707 #endif
708