[FFmpeg-devel] [PATCH] MVI demuxer / Motion Pixels decoder

[Michael Niedermayer]

On Mon, Jul 07, 2008 at 11:30:14PM +0200, Gregory Montoir wrote:
> Michael Niedermayer wrote:
>> On Sat, Jul 05, 2008 at 01:10:15AM +0200, Gregory Montoir wrote:
>>> Michael Niedermayer wrote:
>>>> On Thu, Jul 03, 2008 at 11:40:16PM +0200, Gregory Montoir wrote:
[...]
>> [...]
>>> +    for (y = 0; y < mp->avctx->height; ++y) {
>>> +        if (mp->changes_map[y * mp->avctx->width] != 0) {
>>> +            yp = y;
>>> +        } else {
>>> +            if (yp != -1) {
>>> +                p = mp_get_yuv_from_rgb(mp, 0, yp);
>>> +                memset(mp->gradient_scale, 1, 
>>> sizeof(mp->gradient_scale));
>>> +                yp = -1;
>>> +            }
>>> +            p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
>>> +            if ((y & 3) == 0) {
>>> +                p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
>>> +                p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
>>> +            }
>>> +            mp->vpt[y] = p;
>>> +            mp_set_rgb_from_yuv(mp, 0, y, &p);
>>> +        }
>>> +    }
>> for (y = 0; y < mp->avctx->height; ++y) {
>>     if (mp->changes_map[y * mp->avctx->width]) {
>>         p = mp_get_yuv_from_rgb(mp, 0, y);
>>         memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
>>     } else {
>>         p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
>>         if ((y & 3) == 0) {
>>             p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
>>             p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
>>         }
>>         mp->vpt[y] = p;
>>         mp_set_rgb_from_yuv(mp, 0, y, &p);
>>     }
>> }
>
> haven't changed for the moment. the idea was avoid the calls to memset() 
> and yuv_to_rgb() if there were not necessary (changes_map[y] can be != 0 
> for several consecutives lines and only the previous line is used when 
> applying the deltas).

What speed difference does it make?


[...]
> +typedef struct HuffCode {
> +    int delta;

uint8_t is enough


> +    int code;

> +    int size;

uint8_t is enough


[...]
> +static av_cold int mp_decode_init(AVCodecContext *avctx)
> +{
> +    MotionPixelsContext *mp = avctx->priv_data;
> +

> +    if (!(mp_rgb_yuv_table[0].u | mp_rgb_yuv_table[0].v | mp_rgb_yuv_table[0].y)) {

2 of these are unneeded


[...]
> +static void mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
> +{
> +    while (get_bits1(gb)) {
> +        ++size;

> +        if (size > mp->max_codes_bits)
> +            break;
> +        code <<= 1;
> +        mp_get_code(mp, gb, size, code + 1);
> +    }
> +    if (mp->current_codes_count < MAX_HUFF_CODES) {
> +        mp->codes[mp->current_codes_count  ].code = code;
> +        mp->codes[mp->current_codes_count++].size = size;
> +    }

some error messages would be nice for these error conditions


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When the tyrant has disposed of foreign enemies by conquest or treaty, and
there is nothing more to fear from them, then he is always stirring up
some war or other, in order that the people may require a leader. -- Plato
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20080709/2ba51874/attachment.pgp>