On 10/30/22, James Almer <jamr...@gmail.com> wrote:
> On 10/30/2022 3:29 PM, Paul B Mahol wrote:
>> On 10/30/22, James Almer <jamr...@gmail.com> wrote:
>>>
>>>
>>> On 10/30/2022 3:19 PM, Paul B Mahol wrote:
>>>> On 10/30/22, James Almer <jamr...@gmail.com> wrote:
>>>>> On 10/30/2022 12:34 PM, Paul B Mahol wrote:
>>>>>> +static const struct {
>>>>>> + const int order;
>>>>>> + const int inputs;
>>>>>> + const int speakers;
>>>>>> + const int near_field;
>>>>>> + const int type;
>>>>>> + const double xover;
>>>>>> + const AVChannelLayout outlayout;
>>>>>> + const double *speakers_azimuth;
>>>>>> + const double *speakers_elevation;
>>>>>> + const double *speakers_distance;
>>>>>> +} ambisonic_tab[] = {
>>>>>> + [MONO] = {
>>>>>> + .order = 0,
>>>>>> + .inputs = 1,
>>>>>> + .speakers = 1,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO,
>>>>>> + .speakers_azimuth = (const double[1]){ 0. },
>>>>>> + .speakers_distance = (const double[1]){ 1. },
>>>>>> + },
>>>>>> + [STEREO] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 2,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO,
>>>>>> + .speakers_azimuth = (const double[2]){ -30, 30},
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [STEREO_DOWNMIX] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 2,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout =
>>>>>> (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO_DOWNMIX,
>>>>>> + .speakers_azimuth = (const double[2]){ -90, 90 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [SURROUND] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 3,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_SURROUND,
>>>>>> + .speakers_azimuth = (const double[3]){ -45, 45, 0 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [L2_1] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 3,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_2_1,
>>>>>> + .speakers_azimuth = (const double[3]){ -45, 45, 180 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [TRIANGLE] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 3,
>>>>>> + .type = 1,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_SURROUND,
>>>>>> + .speakers_azimuth = (const double[3]){ -120, 120, 0 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [QUAD] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 4,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_QUAD,
>>>>>> + .speakers_azimuth = (const double[4]){ -45, 45, -135, 135 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [SQUARE] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 4,
>>>>>> + .type = 1,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_4POINT0,
>>>>>> + .speakers_azimuth = (const double[4]){ 0, -90, 180, 90 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [L4_0] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 4,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_4POINT0,
>>>>>> + .speakers_azimuth = (const double[4]){ -30, 30, 0, 180 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [L5_0] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 5,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout =
>>>>>> (AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT0_BACK,
>>>>>> + .speakers_azimuth = (const double[5]){ -30, 30, 0, -145, 145
>>>>>> },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [L5_0_SIDE] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 5,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT0,
>>>>>> + .speakers_azimuth = (const double[5]){ -30, 30, 0, -110, 110
>>>>>> },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [L6_0] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 6,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_6POINT0,
>>>>>> + .speakers_azimuth = (const double[6]){ -30, 30, 0, 180,
>>>>>> -110,
>>>>>> 110
>>>>>> },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [L7_0] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 7,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_7POINT0,
>>>>>> + .speakers_azimuth = (const double[7]){ -30, 30, 0, -145,
>>>>>> 145,
>>>>>> -110, 110 },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [TETRA] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 4,
>>>>>> + .type = 2,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_QUAD,
>>>>>> + .speakers_azimuth = (const double[4]){ -90, 90, 0, 180 },
>>>>>> + .speakers_elevation = (const double[4]){ -35.3, -35.3, 35.3,
>>>>>> 35.3
>>>>>> },
>>>>>> + .speakers_distance = same_distance,
>>>>>> + },
>>>>>> + [CUBE] = {
>>>>>> + .order = 1,
>>>>>> + .inputs = 4,
>>>>>> + .speakers = 8,
>>>>>> + .type = 2,
>>>>>> + .near_field = NF_NONE,
>>>>>> + .xover = 0.,
>>>>>> + .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_7POINT1,
>>>>>
>>>>> 7.1 defines an LFE channel, which is clearly not intended here, so it
>>>>> should be either:
>>>>>
>>>>> .outlayout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MASK(8,
>>>>> AV_CH_LAYOUT_QUAD |
>>>>> AV_CH_TOP_FRONT_LEFT |
>>>>> AV_CH_TOP_FRONT_RIGHT |
>>>>> AV_CH_TOP_BACK_LEFT |
>>>>> AV_CH_TOP_BACK_RIGHT),
>>>>>
>>>>> Or the AV_CHANNEL_LAYOUT_CUBE layout (using the exact same bitmask as
>>>>> above) after the patch i sent just now is committed.
>>>>
>>>> CUBE is as real cube in 3d space. No current layout in API can be
>>>> described correctly.
>>>
>>> the TOP_* channels are in a different height layer than the other
>>> channels, namely above them. The result for this bitmask is a 3D cube
>>> layout (Left and right speakers both front and back, in two different
>>> height layers).
>>
>> https://en.wikipedia.org/wiki/Ambisonic_reproduction_systems#Cube
>
> "If all speakers are placed in room corners", So a 7.1 layout, besides
> defining one channel as LFE, is also not ideal given that it defines two
> speaker positions in places other than the room corners, and by no means
> describes a 3D cube since all speakers are at the same height.
> The TOP channel ids let you assign four channels to speakers placed in
> the top room corners.
7.1 is there just because it have 8 channels. No other reasons.
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