On 11/16/2016 12:33 PM, Vittorio Giovara wrote:
> On Tue, Nov 15, 2016 at 10:09 PM, James Almer <jamr...@gmail.com> wrote:
>> On 11/15/2016 1:56 PM, Vittorio Giovara wrote:
>>> +static int mov_read_st3d(MOVContext *c, AVIOContext *pb, MOVAtom atom)
>>> +{
>>> + AVStream *st;
>>> + MOVStreamContext *sc;
>>> + enum AVStereo3DType type;
>>> + int mode;
>>> +
>>> + if (c->fc->nb_streams < 1)
>>> + return 0;
>>> +
>>> + st = c->fc->streams[c->fc->nb_streams - 1];
>>> + sc = st->priv_data;
>>> +
>>> + if (atom.size < 1) {
>>> + av_log(c->fc, AV_LOG_ERROR, "Empty stereoscopic video box\n");
>>> + return AVERROR_INVALIDDATA;
>>> + }
>>> +
>>> + mode = avio_r8(pb);
>>
>> If i'm reading the spec right, st3d is a FullBox so before the data you'll
>> have the box's version and flags (1 byte and 3 bytes respectively).
>
> Oh I see, so I should check for version == 0 and read three bytes only
> instead of 4.
>
>>> + av_log(c->fc, AV_LOG_ERROR, "Missing projection header box\n");
>>> + return 0;
>>> + }
>>> +
>>> + /* 16.16 fixed point */
>>> + yaw = avio_rb32(pb);
>>> + pitch = avio_rb32(pb);
>>> + roll = avio_rb32(pb);
>>> +
>>> + avio_skip(pb, size - 20);
>>> +
>>> + size = avio_rb32(pb);
>>> + if (size > atom.size)
>>> + return AVERROR_INVALIDDATA;
>>> +
>>> + tag = avio_rl32(pb);
>>
>> And all the possible cases for this one, except in here it seems to be 4
>> bytes for
>> version and four for flags.
In the end no, they apparently are also 1 byte version + 3 bytes flags.
>>
>> Does Google offer samples to confirm this?
>
> Yep.
>
> https://transfer.sh/WOegj/motherboard-cube-v2-metadata.mp4
> https://transfer.sh/31Zvg/motherboard-equirect-v1-metadata.mp4
> https://transfer.sh/tn1xe/motherboard-equirect-v2-metadata.mp4
Nice, thanks. Although it would have been better if they had some values other
than 0 for every spherical related field.
Do they also happen to offer webm samples with the elements detailed in this
spec?
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