From 418c98dec73c0a795ac123f9a3e6888ebda94aa7 Mon Sep 17 00:00:00 2001 From: wm4 Date: Mon, 18 Jan 2016 16:31:26 +0100 Subject: af_lavrresample: fudge some channel layout conversion Prevents channels from being dropped, e.g. when going 7.1 -> 7.1(wide) and similar cases. The reasoning here is that channel layouts over HDMI don't work anyway, and not dropping a channel and playing it on a slightly "wrong" (but expected) speaker is preferable to playing silence on these speakers. Do this to remove issues with ao_coreaudio. Frankly I'm not sure whether our mapping (between CA and mpv/FFmpeg speakers) is correct, but on the other hand due to the reasons stated above it's not all that meaningful. --- audio/filter/af_lavrresample.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'audio') diff --git a/audio/filter/af_lavrresample.c b/audio/filter/af_lavrresample.c index f7f448cad0..477443cefc 100644 --- a/audio/filter/af_lavrresample.c +++ b/audio/filter/af_lavrresample.c @@ -179,6 +179,37 @@ bool af_lavrresample_test_conversion(int src_format, int dst_format) check_output_conversion(dst_format) != AV_SAMPLE_FMT_NONE; } +static struct mp_chmap fudge_pairs[][2] = { + {MP_CHMAP2(FLC, FRC), MP_CHMAP2(SL, SR)}, + {MP_CHMAP2(SL, SR), MP_CHMAP2(FLC, FRC)}, + {MP_CHMAP2(SDL, SDR), MP_CHMAP2(SL, SR)}, + {MP_CHMAP2(SL, SR), MP_CHMAP2(SDL, SDR)}, +}; + +// Modify out_layout and return the new value. The intention is reducing the +// loss libswresample's rematrixing will cause by exchanging similar, but +// strictly speaking incompatible channel pairs. For example, 7.1 should be +// changed to 7.1(wide) without dropping the SL/SR channels. (We still leave +// it to libswresample to create the remix matrix.) +static uint64_t fudge_layout_conversion(struct af_instance *af, + uint64_t in, uint64_t out) +{ + for (int n = 0; n < MP_ARRAY_SIZE(fudge_pairs); n++) { + uint64_t a = mp_chmap_to_lavc(&fudge_pairs[n][0]); + uint64_t b = mp_chmap_to_lavc(&fudge_pairs[n][1]); + if ((in & a) == a && (in & b) == 0 && + (out & a) == 0 && (out & b) == b) + { + out = (out & ~b) | a; + + MP_VERBOSE(af, "Fudge: %s -> %s\n", + mp_chmap_to_str(&fudge_pairs[n][0]), + mp_chmap_to_str(&fudge_pairs[n][1])); + } + } + return out; +} + // mp_chmap_get_reorder() performs: // to->speaker[n] = from->speaker[src[n]] // but libavresample does: @@ -297,6 +328,8 @@ static int configure_lavrr(struct af_instance *af, struct mp_audio *in, if (map_out.num > out_lavc.num) mp_audio_set_channels(&s->pool_fmt, &map_out); + out_ch_layout = fudge_layout_conversion(af, in_ch_layout, out_ch_layout); + // Real conversion; output is input to avrctx_out. av_opt_set_int(s->avrctx, "in_channel_layout", in_ch_layout, 0); av_opt_set_int(s->avrctx, "out_channel_layout", out_ch_layout, 0); -- cgit v1.2.3