[FFmpeg-devel] [PATCH 7/7] avcodec/aacdec_template: add support for 22.2 / channel_config 13

[Paul B Mahol]

I think there is open bug report about SEGV regarding this commit on trac.

Please revert or fix ASAP!

On 8/16/20, Michael Niedermayer <michael at niedermayer.cc> wrote:
> On Sat, Aug 01, 2020 at 02:07:30PM +0300, Jan Ekström wrote:
>> ---
>>  libavcodec/aacdec_template.c | 89 +++++++++++++++++++++++++++++++-----
>>  1 file changed, 78 insertions(+), 11 deletions(-)
>>
>> diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
>> index 21db12fdab..8c5048cc13 100644
>> --- a/libavcodec/aacdec_template.c
>> +++ b/libavcodec/aacdec_template.c
>> @@ -387,17 +387,77 @@ static uint64_t sniff_channel_order(uint8_t
>> (*layout_map)[3], int tags)
>>          i++;
>>      }
>>
>> -    // Must choose a stable sort
>> +    // The previous checks would end up at 8 at this point for 22.2
>> +    if (tags == 16 && i == 8) {
>> +        e2c_vec[i] = (struct elem_to_channel) {
>> +            .av_position  = AV_CH_TOP_FRONT_CENTER,
>> +            .syn_ele      = layout_map[i][0],
>> +            .elem_id      = layout_map[i][1],
>> +            .aac_position = layout_map[i][2]
>> +        }; i++;
>> +        i += assign_pair(e2c_vec, layout_map, i,
>> +                         AV_CH_TOP_FRONT_LEFT,
>> +                         AV_CH_TOP_FRONT_RIGHT,
>> +                         AAC_CHANNEL_FRONT);
>> +        i += assign_pair(e2c_vec, layout_map, i,
>> +                         AV_CH_TOP_SIDE_LEFT,
>> +                         AV_CH_TOP_SIDE_RIGHT,
>> +                         AAC_CHANNEL_SIDE);
>> +        e2c_vec[i] = (struct elem_to_channel) {
>> +            .av_position  = AV_CH_TOP_CENTER,
>> +            .syn_ele      = layout_map[i][0],
>> +            .elem_id      = layout_map[i][1],
>> +            .aac_position = layout_map[i][2]
>> +        }; i++;
>> +        i += assign_pair(e2c_vec, layout_map, i,
>> +                         AV_CH_TOP_BACK_LEFT,
>> +                         AV_CH_TOP_BACK_RIGHT,
>> +                         AAC_CHANNEL_BACK);
>> +        e2c_vec[i] = (struct elem_to_channel) {
>> +            .av_position  = AV_CH_TOP_BACK_CENTER,
>> +            .syn_ele      = layout_map[i][0],
>
> Does this code assume all types are CPE ?
> because if thats not true i can exceed the tags
>
>
>> +            .elem_id      = layout_map[i][1],
>> +            .aac_position = layout_map[i][2]
>> +        }; i++;
>> +        e2c_vec[i] = (struct elem_to_channel) {
>> +            .av_position  = AV_CH_BOTTOM_FRONT_CENTER,
>> +            .syn_ele      = layout_map[i][0],
>> +            .elem_id      = layout_map[i][1],
>> +            .aac_position = layout_map[i][2]
>> +        }; i++;
>> +        i += assign_pair(e2c_vec, layout_map, i,
>> +                         AV_CH_BOTTOM_FRONT_LEFT,
>> +                         AV_CH_BOTTOM_FRONT_RIGHT,
>> +                         AAC_CHANNEL_FRONT);
>> +    }
>> +
>>      total_non_cc_elements = n = i;
>> -    do {
>> -        int next_n = 0;
>> -        for (i = 1; i < n; i++)
>> -            if (e2c_vec[i - 1].av_position > e2c_vec[i].av_position) {
>> -                FFSWAP(struct elem_to_channel, e2c_vec[i - 1],
>> e2c_vec[i]);
>> -                next_n = i;
>> -            }
>> -        n = next_n;
>> -    } while (n > 0);
>> +
>> +    if (tags == 16 && total_non_cc_elements == 16) {
>> +        // For 22.2 reorder the result as needed
>> +        FFSWAP(struct elem_to_channel, e2c_vec[2], e2c_vec[0]);   // FL &
>> FR first (final), FC third
>> +        FFSWAP(struct elem_to_channel, e2c_vec[2], e2c_vec[1]);   // FC
>> second (final), FLc & FRc third
>> +        FFSWAP(struct elem_to_channel, e2c_vec[6], e2c_vec[2]);   // LFE1
>> third (final), FLc & FRc seventh
>> +        FFSWAP(struct elem_to_channel, e2c_vec[4], e2c_vec[3]);   // BL &
>> BR fourth (final), SiL & SiR fifth
>> +        FFSWAP(struct elem_to_channel, e2c_vec[6], e2c_vec[4]);   // FLc
>> & FRc fifth (final), SiL & SiR seventh
>> +        FFSWAP(struct elem_to_channel, e2c_vec[7], e2c_vec[6]);   // LFE2
>> seventh (final), SiL & SiR eight (final)
>> +        FFSWAP(struct elem_to_channel, e2c_vec[9], e2c_vec[8]);   // TpFL
>> & TpFR ninth (final), TFC tenth (final)
>> +        FFSWAP(struct elem_to_channel, e2c_vec[11], e2c_vec[10]); // TC
>> eleventh (final), TpSiL & TpSiR twelth
>> +        FFSWAP(struct elem_to_channel, e2c_vec[12], e2c_vec[11]); // TpBL
>> & TpBR twelth (final), TpSiL & TpSiR thirteenth (final)
>
> Does this not need to check the assumtations from the comments ?
>
> thx
>
> [...]
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Awnsering whenever a program halts or runs forever is
> On a turing machine, in general impossible (turings halting problem).
> On any real computer, always possible as a real computer has a finite
> number
> of states N, and will either halt in less than N cycles or never halt.
>