[FFmpeg-devel] [PATCH v5] lavc/rawdec: Use AV_PIX_FMT_PAL8 for 1-bit raw AVI video, and more
Michael Niedermayer
michael at niedermayer.cc
Mon Jan 25 01:14:28 CET 2016
On Fri, Jan 22, 2016 at 03:44:30PM +0100, Mats Peterson wrote:
> You'll have to excuse me, Michael, but the changes I've made,
> including the line alignment changes, are dependent on each other,
> and not easy or very logical to split. Here's a new version that
> displays the Matrix video correctly.
>
> Mats
>
> --
> Mats Peterson
> http://matsp888.no-ip.org/~mats/
> raw.c | 2 -
> rawdec.c | 92 +++++++++++++++++++++++++++++++++++++++++----------------------
> 2 files changed, 62 insertions(+), 32 deletions(-)
> 7e3ead59067fc542c5ad6c3231ab5783bad57c0b 0001-lavc-rawdec-Use-AV_PIX_FMT_PAL8-for-1-bit-raw-AVI-vi.patch
> From 0f99c5bdcf39230556eef82fa849dd6342208539 Mon Sep 17 00:00:00 2001
> From: Mats Peterson <matsp888 at yahoo.com>
> Date: Fri, 22 Jan 2016 15:38:26 +0100
> Subject: [PATCH v5] lavc/rawdec: Use AV_PIX_FMT_PAL8 for 1-bit raw AVI video, and more
>
> 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_decoder().
>
> Also, the line alignment for 4 bpp and 8 bpp depths generated warning
> messages. The line alignment is now 16 bytes for 1, 2, 4, and 8 bpp depth.
>
> Mats
>
> ---
> libavcodec/raw.c | 2 +-
> libavcodec/rawdec.c | 92 ++++++++++++++++++++++++++++++++++-----------------
> 2 files changed, 62 insertions(+), 32 deletions(-)
>
> diff --git a/libavcodec/raw.c b/libavcodec/raw.c
> index 3f2cc11..3979c5c 100644
> --- a/libavcodec/raw.c
> +++ b/libavcodec/raw.c
> @@ -242,7 +242,7 @@ unsigned int avcodec_pix_fmt_to_codec_tag(enum AVPixelFormat fmt)
> }
>
> const PixelFormatTag avpriv_pix_fmt_bps_avi[] = {
> - { AV_PIX_FMT_MONOWHITE, 1 },
> + { AV_PIX_FMT_PAL8, 1 },
> { AV_PIX_FMT_PAL8, 2 },
> { AV_PIX_FMT_PAL8, 4 },
> { AV_PIX_FMT_PAL8, 8 },
> diff --git a/libavcodec/rawdec.c b/libavcodec/rawdec.c
> index cb0364c..9c4e69a 100644
> --- a/libavcodec/rawdec.c
> +++ b/libavcodec/rawdec.c
> @@ -41,7 +41,7 @@ typedef struct RawVideoContext {
> AVBufferRef *palette;
> int frame_size; /* size of the frame in bytes */
> int flip;
> - int is_1_2_4_bpp; // 1 bpp raw in mov, and 2 or 4 bpp raw in avi/mov
> + int is_1_2_4_8_bpp; // 1, 2, 4 and 8 bpp raw in avi/mov
> int is_yuv2;
> int is_lt_16bpp; // 16bpp pixfmt and bits_per_coded_sample < 16
> int tff;
> @@ -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);
> + }
> }
>
> if ((avctx->extradata_size >= 9 &&
> @@ -153,19 +156,20 @@ static int raw_decode(AVCodecContext *avctx, void *data, int *got_frame,
> RawVideoContext *context = avctx->priv_data;
> const uint8_t *buf = avpkt->data;
> int buf_size = avpkt->size;
> + int avpkt_stride = avpkt->size / avctx->height;
> int linesize_align = 4;
> int res, len;
> int need_copy;
>
> AVFrame *frame = data;
>
> - if ((avctx->bits_per_coded_sample == 4 || avctx->bits_per_coded_sample == 2
> - || avctx->bits_per_coded_sample == 1) &&
> + if ((avctx->bits_per_coded_sample == 8 || avctx->bits_per_coded_sample == 4
> + || avctx->bits_per_coded_sample == 2 || avctx->bits_per_coded_sample == 1) &&
> avctx->pix_fmt == AV_PIX_FMT_PAL8 &&
> (!avctx->codec_tag || avctx->codec_tag == MKTAG('r','a','w',' '))) {
> - context->is_1_2_4_bpp = 1;
> + context->is_1_2_4_8_bpp = 1;
> context->frame_size = av_image_get_buffer_size(avctx->pix_fmt,
> - FFALIGN(avctx->width, 32),
> + FFALIGN(avctx->width, 16),
> avctx->height, 1);
> } else {
> context->is_lt_16bpp = av_get_bits_per_pixel(desc) == 16 && avctx->bits_per_coded_sample && avctx->bits_per_coded_sample < 16;
> @@ -175,7 +179,7 @@ static int raw_decode(AVCodecContext *avctx, void *data, int *got_frame,
> if (context->frame_size < 0)
> return context->frame_size;
>
> - need_copy = !avpkt->buf || context->is_1_2_4_bpp || context->is_yuv2 || context->is_lt_16bpp;
> + need_copy = !avpkt->buf || context->is_1_2_4_8_bpp || context->is_yuv2 || context->is_lt_16bpp;
>
> frame->pict_type = AV_PICTURE_TYPE_I;
> frame->key_frame = 1;
> @@ -202,39 +206,65 @@ static int raw_decode(AVCodecContext *avctx, void *data, int *got_frame,
> if (!frame->buf[0])
> return AVERROR(ENOMEM);
>
> - // 1 bpp raw in mov, and 2 or 4 bpp raw in avi/mov
> - if (context->is_1_2_4_bpp) {
> - int i;
> + // 1, 2, 4 and 8 bpp raw in avi/mov
> + if (context->is_1_2_4_8_bpp) {
> + int i, j, row_pix = 0;
> uint8_t *dst = frame->buf[0]->data;
> buf_size = context->frame_size - AVPALETTE_SIZE;
> - if (avctx->bits_per_coded_sample == 4) {
> - for (i = 0; 2 * i + 1 < buf_size && i<avpkt->size; i++) {
> - dst[2 * i + 0] = buf[i] >> 4;
> - dst[2 * i + 1] = buf[i] & 15;
> + if (avctx->bits_per_coded_sample == 8) {
> + for (i = 0, j = 0; j < buf_size && i<avpkt->size; i++, j++) {
> + dst[j] = buf[i];
> + row_pix++;
> + if (row_pix == avctx->width) {
> + i += avpkt_stride - (i % avpkt_stride) - 1;
> + j += 16 - (j % 16) - 1;
> + row_pix = 0;
> + }
> + }
> + } else if (avctx->bits_per_coded_sample == 4) {
> + for (i = 0, j = 0; 2 * j + 1 < buf_size && i<avpkt->size; i++, j++) {
> + dst[2 * j + 0] = buf[i] >> 4;
> + dst[2 * j + 1] = buf[i] & 15;
> + row_pix += 2;
> + if (row_pix >= avctx->width) {
> + i += avpkt_stride - (i % avpkt_stride) - 1;
> + j += 8 - (j % 8) - 1;
> + row_pix = 0;
> + }
> }
> - linesize_align = 8;
decreasing linesize_align below the SIMD register size is undesirable
as it could lead to unaligned accesses in subsequent code using
the frames which would cause speedloss
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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