On 08/28/2017 11:26 AM, Alexis Ballier wrote:
Hi,
On Sun, 27 Aug 2017 21:41:06 +0200
Jorge Ramirez <jorge.ramirez-or...@linaro.org> wrote:
On 08/27/2017 09:09 PM, Jorge Ramirez wrote:
On 08/25/2017 05:35 PM, wm4 wrote:
+static int buffer_ops_v4l2buf_to_avframe(AVFrame *frame,
V4L2Buffer *avbuf) +{
+ int i, ret;
+
+ av_frame_unref(frame);
+
+ /* 1. get references to the actual data */
+ for (i = 0; i < avbuf->num_planes; i++) {
+ ret = avbuf->ops.buf_to_bufref(avbuf, i, &frame->buf[i]);
+ if (ret)
+ return ret;
+
+ frame->linesize[i] = avbuf->bytesperline[i];
+ frame->data[i] = frame->buf[i]->data;
+ }
+
+ /* 1.1 fixup special cases */
+ switch (avbuf->context->av_pix_fmt) {
+ case AV_PIX_FMT_NV12:
+ if (avbuf->num_planes > 1)
+ break;
+ frame->linesize[1] = avbuf->bytesperline[0];
+ frame->data[1] = frame->buf[0]->data +
avbuf->bytesperline[0] * avbuf->context->format.fmt.pix_mp.height;
+ break;
+ default:
+ break;
+ }
+
+ /* 2. get frame information */
+ frame->key_frame = !!(avbuf->buf.flags &
V4L2_BUF_FLAG_KEYFRAME);
+ frame->format = avbuf->context->av_pix_fmt;
+
+ /* these values are updated also during re-init in
process_video_event */
+ frame->height = avbuf->context->height;
+ frame->width = avbuf->context->width;
+ frame->pts = get_pts(avbuf);
+
+ /* 3. report errors upstream */
+ if (avbuf->buf.flags & V4L2_BUF_FLAG_ERROR) {
+ av_log(avbuf->context->log_ctx, AV_LOG_ERROR, "%s:
driver decode error\n", avbuf->context->name);
+ frame->decode_error_flags |=
FF_DECODE_ERROR_INVALID_BITSTREAM;
+ }
+
+ return 0;
+}
This function seems to lack setting typically required metadata
like colorspace.
ok I will retrieve the colorspace from the v4l2 format structure
and set it in the frame.
um, I dont see a 1:1 mapping between the colorspaces reported from
v4l2 and what ffmpeg expects (I am also not a subject matter expert
on this :( ).
Could I get some guidance on the translation table below please?
btw in my simple tests - ffplay decoded vp8, vp9, mpeg4, mpeg2, h263,
h264 and hevc I didnt need this field so I am not sure if I am
getting it right.
I don't think it will affect decoding, but the image will be something like too
pale if it's set wrongly
static inline enum AVColorSpace get_colorspace(V4L2Buffer *buf)
{
enum v4l2_colorspace cs;
cs = V4L2_TYPE_IS_MULTIPLANAR(buf->context->type) ?
buf->context->format.fmt.pix_mp.colorspace :
buf->context->format.fmt.pix.colorspace;
/* */
switch (cs) {
case V4L2_COLORSPACE_SMPTE170M: return AVCOL_SPC_SMPTE170M;
case V4L2_COLORSPACE_SMPTE240M: return AVCOL_SPC_SMPTE240M;
case V4L2_COLORSPACE_470_SYSTEM_BG: return AVCOL_SPC_BT470BG;
case V4L2_COLORSPACE_BT2020: return AVCOL_SPC_BT2020_CL;
case V4L2_COLORSPACE_REC709: return AVCOL_SPC_BT709;
case V4L2_COLORSPACE_ADOBERGB:
case V4L2_COLORSPACE_SRGB:
case V4L2_COLORSPACE_DCI_P3:
case V4L2_COLORSPACE_JPEG:
case V4L2_COLORSPACE_RAW:
default:
return AVCOL_SPC_RGB;
}
FWIW, here is the conversion I had been using in other projects:
switch(f->colorspace)
{
case V4L2_COLORSPACE_SRGB:
return AVCOL_SPC_RGB;
case V4L2_COLORSPACE_REC709:
return AVCOL_SPC_BT709;
case V4L2_COLORSPACE_470_SYSTEM_M:
return AVCOL_SPC_FCC;
case V4L2_COLORSPACE_470_SYSTEM_BG:
return AVCOL_SPC_BT470BG;
case V4L2_COLORSPACE_SMPTE170M:
return AVCOL_SPC_SMPTE170M;
case V4L2_COLORSPACE_SMPTE240M:
return AVCOL_SPC_SMPTE240M;
case V4L2_COLORSPACE_BT2020:
if(f->ycbcr_enc == V4L2_YCBCR_ENC_BT2020_CONST_LUM)
return AVCOL_SPC_BT2020_CL;
return AVCOL_SPC_BT2020_NCL;
default: return AVCOL_SPC_UNSPECIFIED;
}
you'd likely need AVCOL_PRI*:
switch(f->ycbcr_enc)
{
case V4L2_YCBCR_ENC_XV709:
case V4L2_YCBCR_ENC_709 :
return AVCOL_PRI_BT709;
case V4L2_YCBCR_ENC_XV601:
case V4L2_YCBCR_ENC_601:
return AVCOL_PRI_BT470M;
default: break;
}
switch(f->colorspace)
{
case V4L2_COLORSPACE_470_SYSTEM_BG:
return AVCOL_PRI_BT470BG;
case V4L2_COLORSPACE_SMPTE170M:
return AVCOL_PRI_SMPTE170M;
case V4L2_COLORSPACE_SMPTE240M:
return AVCOL_PRI_SMPTE240M;
case V4L2_COLORSPACE_BT2020:
return AVCOL_PRI_BT2020;
default: break;
}
return AVCOL_PRI_UNSPECIFIED;
AVCOL_TRC*:
switch(f->xfer_func)
{
case V4L2_XFER_FUNC_709:
switch(f->bit_depth)
{
case 10: return AVCOL_TRC_BT2020_10;
case 12: return AVCOL_TRC_BT2020_12;
default: break;
}
return AVCOL_TRC_BT709;
case V4L2_XFER_FUNC_SRGB:
return AVCOL_TRC_IEC61966_2_1;
default: break;
}
switch(f->colorspace)
{
case V4L2_COLORSPACE_470_SYSTEM_M:
return AVCOL_TRC_GAMMA22;
case V4L2_COLORSPACE_470_SYSTEM_BG:
return AVCOL_TRC_GAMMA28;
case V4L2_COLORSPACE_SMPTE170M:
return AVCOL_TRC_SMPTE170M;
case V4L2_COLORSPACE_SMPTE240M:
return AVCOL_TRC_SMPTE240M;
default: break;
}
switch(f->ycbcr_enc)
{
case V4L2_YCBCR_ENC_XV709:
case V4L2_YCBCR_ENC_XV601:
return AVCOL_TRC_BT1361_ECG;
default: break;
}
return AVCOL_TRC_UNSPECIFIED;
AVCOL_RANGE*:
switch(f->quantization)
{
case V4L2_QUANTIZATION_LIM_RANGE:
return AVCOL_RANGE_MPEG;
case V4L2_QUANTIZATION_FULL_RANGE:
return AVCOL_RANGE_JPEG;
default: break;
}
return AVCOL_RANGE_UNSPECIFIED;
Feel free to re-use, point and/or fix bugs here (it's been long since I wrote
this and I don't think I've ever visually checked all the possibilities).
This might also be useful for the V4L2 output and capture drivers in lavd.
awesome. thanks a lot for this information, will merge!
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