diff options
Diffstat (limited to 'audio')
| -rw-r--r-- | audio/chmap.c | 23 | ||||
| -rw-r--r-- | audio/chmap.h | 5 | ||||
| -rw-r--r-- | audio/chmap_sel.c | 94 | ||||
| -rw-r--r-- | audio/chmap_sel.h | 1 |
4 files changed, 123 insertions, 0 deletions
diff --git a/audio/chmap.c b/audio/chmap.c index 64b56b93b2..497b910cff 100644 --- a/audio/chmap.c +++ b/audio/chmap.c @@ -375,6 +375,29 @@ void mp_chmap_get_reorder(int dst[MP_NUM_CHANNELS], const struct mp_chmap *from, assert(to->speaker[dst[n]] == from->speaker[n]); } +// Performs the difference between a and b, and store it in diff. If b has +// channels that do not appear in a, those will not appear in the difference. +// To get to those the argument ordering in the function call has to be +// inverted. For the same reason, the diff with a superset will return no +// speakers. +void mp_chmap_diff(const struct mp_chmap *a, const struct mp_chmap *b, + struct mp_chmap *diff) +{ + uint64_t a_mask = mp_chmap_to_lavc_unchecked(a); + uint64_t b_mask = mp_chmap_to_lavc_unchecked(b); + mp_chmap_from_lavc(diff, (a_mask ^ b_mask) & a_mask); +} + +// Checks whether a contains all the speakers in b +bool mp_chmap_contains(const struct mp_chmap *a, const struct mp_chmap *b) +{ + struct mp_chmap d1; + struct mp_chmap d2; + mp_chmap_diff(a, b, &d1); + mp_chmap_diff(b, a, &d2); + return a->num >= b->num && d1.num >= 0 && d2.num == 0; +} + // Returns something like "fl-fr-fc". If there's a standard layout in lavc // order, return that, e.g. "3.0" instead of "fl-fr-fc". // Unassigned but valid speakers get names like "sp28". diff --git a/audio/chmap.h b/audio/chmap.h index d0b9806ff5..9ec1c12d7b 100644 --- a/audio/chmap.h +++ b/audio/chmap.h @@ -120,6 +120,11 @@ void mp_chmap_reorder_to_lavc(struct mp_chmap *map); void mp_chmap_get_reorder(int dst[MP_NUM_CHANNELS], const struct mp_chmap *from, const struct mp_chmap *to); +void mp_chmap_diff(const struct mp_chmap *a, const struct mp_chmap *b, + struct mp_chmap *diff); + +bool mp_chmap_contains(const struct mp_chmap *a, const struct mp_chmap *b); + char *mp_chmap_to_str_buf(char *buf, size_t buf_size, const struct mp_chmap *src); #define mp_chmap_to_str(m) mp_chmap_to_str_buf((char[64]){0}, 64, (m)) diff --git a/audio/chmap_sel.c b/audio/chmap_sel.c index fe0b9598a0..23ebe71710 100644 --- a/audio/chmap_sel.c +++ b/audio/chmap_sel.c @@ -17,6 +17,7 @@ #include <stdlib.h> #include <assert.h> +#include <limits.h> #include "common/common.h" #include "chmap_sel.h" @@ -183,6 +184,10 @@ bool mp_chmap_sel_adjust(const struct mp_chmap_sel *s, struct mp_chmap *map) return true; } } + + if (mp_chmap_sel_fallback(s, map)) + return true; + // Fallback to mono/stereo as last resort *map = (struct mp_chmap) MP_CHMAP_INIT_STEREO; if (test_layout(s, map)) @@ -194,6 +199,95 @@ bool mp_chmap_sel_adjust(const struct mp_chmap_sel *s, struct mp_chmap *map) return false; } +#define UPMIX_IDX 0 +#define DOWNMIX_IDX 1 +#define FALLBACK_IDX 2 + +static bool test_fallbacks(struct mp_chmap *a, struct mp_chmap *b, + int best_diffs[2], struct mp_chmap best[2]) +{ + struct mp_chmap diff1, diff2; + + mp_chmap_diff(a, b, &diff1); + if (mp_chmap_contains(a, b) && best_diffs[UPMIX_IDX] > diff1.num) { + best[UPMIX_IDX] = *a; + best_diffs[UPMIX_IDX] = diff1.num; + return true; + } + + mp_chmap_diff(b, a, &diff2); + if (mp_chmap_contains(b, a) && best_diffs[DOWNMIX_IDX] > diff2.num) { + best[DOWNMIX_IDX] = *a; + best_diffs[DOWNMIX_IDX] = diff2.num; + return true; + } + + if (diff1.num > 0 && best_diffs[FALLBACK_IDX] > diff1.num) { + best[FALLBACK_IDX] = *a; + best_diffs[FALLBACK_IDX] = diff1.num; + return true; + } + + if (diff2.num > 0 && best_diffs[FALLBACK_IDX] > diff2.num) { + best[FALLBACK_IDX] = *a; + best_diffs[FALLBACK_IDX] = diff2.num; + return true; + } + + return false; +} + +// Determine which channel map to fallback to given a source channel map. It +// uses the following heuristic: +// 1) If mono is required always prefer stereo to a multichannel upmix. +// 2) Search for an upmix that is an exact superset of the required chmap. +// 3) Search for a downmix that is the exact subset of the required chmap. +// 4) Search for either an upmix or downmix that is the closest (minimum +// difference of speakers) to the required chmap. +bool mp_chmap_sel_fallback(const struct mp_chmap_sel *s, struct mp_chmap *map) +{ + // special case: if possible always fallback mono to stereo (instead of + // looking for a multichannel upmix) + struct mp_chmap mono = MP_CHMAP_INIT_MONO; + struct mp_chmap stereo = MP_CHMAP_INIT_STEREO; + if (mp_chmap_equals(&mono, map) && test_layout(s, &stereo)) { + *map = stereo; + return true; + } + + int best_diffs[] = { INT_MAX, INT_MAX, INT_MAX }; + struct mp_chmap best[] = { {0}, {0}, {0} }; + + for (int n = 0; n < s->num_chmaps; n++) { + struct mp_chmap e = s->chmaps[n]; + + if (mp_chmap_is_unknown(&e)) + continue; + + if (test_fallbacks(&e, map, best_diffs, best)) + continue; + + // in case we didn't match any fallback retry after replacing speakers + for (int i = 0; i < MP_ARRAY_SIZE(speaker_replacements); i++) { + struct mp_chmap t = e; + struct mp_chmap *r = (struct mp_chmap *)speaker_replacements[i]; + if (replace_speakers(&t, r)) { + if (test_fallbacks(&t, map, best_diffs, best)) + continue; + } + } + } + + for (int i = UPMIX_IDX; i < MP_ARRAY_SIZE(best); i++) { + if (best_diffs[i] < INT_MAX) { + *map = best[i]; + return true; + } + } + + return false; +} + // Set map to a default layout with num channels. Used for audio APIs that // return a channel count as part of format negotiation, but give no // information about the channel layout. diff --git a/audio/chmap_sel.h b/audio/chmap_sel.h index 7758ca5d74..ae80fa5bc3 100644 --- a/audio/chmap_sel.h +++ b/audio/chmap_sel.h @@ -41,6 +41,7 @@ void mp_chmap_sel_add_alsa_def(struct mp_chmap_sel *s); void mp_chmap_sel_add_map(struct mp_chmap_sel *s, const struct mp_chmap *map); void mp_chmap_sel_add_speaker(struct mp_chmap_sel *s, int id); bool mp_chmap_sel_adjust(const struct mp_chmap_sel *s, struct mp_chmap *map); +bool mp_chmap_sel_fallback(const struct mp_chmap_sel *s, struct mp_chmap *map); bool mp_chmap_sel_get_def(const struct mp_chmap_sel *s, struct mp_chmap *map, int num); |