[FFmpeg-devel] [PATCH v3] lavc/rawdec: Use AV_PIX_FMT_PAL8 for 1-bit raw AVI video
Mats Peterson
matsp888 at yahoo.com
Mon Jan 25 01:30:01 CET 2016
On 01/25/2016 01:26 AM, Michael Niedermayer wrote:
> On Wed, Jan 20, 2016 at 12:41:22PM +0100, Mats Peterson wrote:
>> I don't know about this one, since it adds some calculations inside
>> the loop, but it limits the line alignment to 16 bytes instead of 32
>> bytes as before. Less overhead.
>>
>> Mats
>>
>> --
>> Mats Peterson
>> http://matsp888.no-ip.org/~mats/
>
>> raw.c | 2 +-
>> rawdec.c | 38 ++++++++++++++++++++++++--------------
>> 2 files changed, 25 insertions(+), 15 deletions(-)
>> 3c94aff2647b8a1b0e9c4c147b552c85255253ff 0001-v3.patch
>> From 8d15b348fc84d46f7e764a2e9822aacc80e74407 Mon Sep 17 00:00:00 2001
>> From: Mats Peterson <matsp888 at yahoo.com>
>> Date: Wed, 20 Jan 2016 12:37:40 +0100
>> Subject: [PATCH v3] lavc/rawdec: Use AV_PIX_FMT_PAL8 for 1-bit raw AVI video
>>
>> The stuff about 1-bit video not necessarily being black & white in
>> QuickTime goes for AVI as well. Being 1 bit per pixel only means that
>> the data is bi-level. The two colors can be any color. Since many
>> 1 bpp AVI files don't have a palette following the BITMAPINFOHEADER,
>> I'm setting a "default" black & white palette in raw_init().
>
> Does the official player from microsoft play such crafted avi files
> with the palette colors or black and white ?
>
>
> [...]
>> @@ -94,8 +94,11 @@ static av_cold int raw_init_decoder(AVCodecContext *avctx)
>> return AVERROR(ENOMEM);
>> if (desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL)
>> avpriv_set_systematic_pal2((uint32_t*)context->palette->data, avctx->pix_fmt);
>> - else
>> + else {
>> memset(context->palette->data, 0, AVPALETTE_SIZE);
>> + if (avctx->bits_per_coded_sample == 1)
>> + memset(context->palette->data, 0xff, 4);
>> + }
>
> hunk split out and applied
>
>
> [...]
>
>> @@ -222,18 +225,25 @@ static int raw_decode(AVCodecContext *avctx, void *data, int *got_frame,
>> }
>> linesize_align = 16;
>> } else {
>> + int j, row_pix = 0;
>> av_assert0(avctx->bits_per_coded_sample == 1);
>> - for (i = 0; 8 * i + 7 < buf_size && i<avpkt->size; i++) {
>> - dst[8 * i + 0] = buf[i] >> 7 & 1;
>> - dst[8 * i + 1] = buf[i] >> 6 & 1;
>> - dst[8 * i + 2] = buf[i] >> 5 & 1;
>> - dst[8 * i + 3] = buf[i] >> 4 & 1;
>> - dst[8 * i + 4] = buf[i] >> 3 & 1;
>> - dst[8 * i + 5] = buf[i] >> 2 & 1;
>> - dst[8 * i + 6] = buf[i] >> 1 & 1;
>> - dst[8 * i + 7] = buf[i] & 1;
>> + for (i = 0, j = 0; 8 * j + 7 < buf_size && i<avpkt->size; i++, j++) {
>> + dst[8 * j + 0] = buf[i] >> 7 & 1;
>> + dst[8 * j + 1] = buf[i] >> 6 & 1;
>> + dst[8 * j + 2] = buf[i] >> 5 & 1;
>> + dst[8 * j + 3] = buf[i] >> 4 & 1;
>> + dst[8 * j + 4] = buf[i] >> 3 & 1;
>> + dst[8 * j + 5] = buf[i] >> 2 & 1;
>> + dst[8 * j + 6] = buf[i] >> 1 & 1;
>> + dst[8 * j + 7] = buf[i] & 1;
>> + row_pix += 8;
>> + if (row_pix >= avctx->width) {
>> + i += 4 - (i % 4) - 1;
>> + j += 2 - (j % 2) - 1;
>> + row_pix = 0;
>> + }
>> }
>> - linesize_align = 32;
>> + linesize_align = 16;
>> }
>
> hunk split out and applied
>
> [...]
>
>
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
Well, this one is still incorrect, since it doesn't cater for different
strides.
Mats
--
Mats Peterson
http://matsp888.no-ip.org/~mats/
More information about the ffmpeg-devel
mailing list