[FFmpeg-devel] [PATCH RFC v2 1/3] fftools: Add thumbnail output to vaapi_h264 decoder

[Zachary Zhou]

This is sample code for reference

HW support for decode+scaling in a single HW command (VDBOX+SFC).
The primary target usage is video analytics, but can be used playback,
transcoding, etc.

For VAAPI -
https://github.com/intel/libva
basically, it allows multiple outputs (in different resolutions) using the decode context in a single call (you can search for “additional_outputs” in va.h).

VAAPI sample code -
https://github.com/intel/libva-utils/commit/957a269f02b00760b7e807643c821ee26abc529b
---
 fftools/ffmpeg_opt.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index 53d688b764..c0dc376541 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -111,6 +111,10 @@ int filter_nbthreads = 0;
 int filter_complex_nbthreads = 0;
 int vstats_version = 2;
 
+int thumbnail_flags = 0;
+int thumbnail_width = 0;
+int thumbnail_height = 0;
+char *thumbnail_format;
 
 static int intra_only         = 0;
 static int file_overwrite     = 0;
@@ -1100,6 +1104,13 @@ static int open_input_file(OptionsContext *o, const char *filename)
         av_dict_set(&o->g->format_opts, "scan_all_pmts", "1", AV_DICT_DONT_OVERWRITE);
         scan_all_pmts_set = 1;
     }
+
+    //thumbnail opt
+    av_dict_set_int(&o->g->codec_opts, "thumbnail_flags", thumbnail_flags, AV_DICT_DONT_OVERWRITE);
+    av_dict_set_int(&o->g->codec_opts, "thumbnail_width", thumbnail_width, AV_DICT_DONT_OVERWRITE);
+    av_dict_set_int(&o->g->codec_opts, "thumbnail_height", thumbnail_height, AV_DICT_DONT_OVERWRITE);
+    av_dict_set(&o->g->codec_opts, "thumbnail_format", thumbnail_format, AV_DICT_DONT_OVERWRITE);
+
     /* open the input file with generic avformat function */
     err = avformat_open_input(&ic, filename, file_iformat, &o->g->format_opts);
     if (err < 0) {
@@ -2898,6 +2909,13 @@ static int opt_vstats_file(void *optctx, const char *opt, const char *arg)
     return 0;
 }
 
+static int opt_thumbnail_format(void *optctx, const char *opt, const char *arg)
+{
+    av_free (thumbnail_format);
+    thumbnail_format = av_strdup (arg);
+    return 0;
+}
+
 static int opt_vstats(void *optctx, const char *opt, const char *arg)
 {
     char filename[40];
@@ -3746,5 +3764,15 @@ const OptionDef options[] = {
     { "filter_hw_device", HAS_ARG | OPT_EXPERT, { .func_arg = opt_filter_hw_device },
         "set hardware device used when filtering", "device" },
 
+    //thumbnail opt
+    { "thumbnail_flags",    OPT_VIDEO | HAS_ARG | OPT_INT | OPT_INPUT, { &thumbnail_flags },
+      "set thumbnail flags", "thumbnail" },
+    { "thumbnail_width",    OPT_VIDEO | HAS_ARG | OPT_INT | OPT_INPUT, { &thumbnail_width },
+      "set thumbnail width", "thumbnail" },
+    { "thumbnail_height",   OPT_VIDEO | HAS_ARG | OPT_INT | OPT_INPUT, { &thumbnail_height },
+      "set thumbnail height", "thumbnail" },
+    { "thumbnail_format",  OPT_VIDEO | HAS_ARG | OPT_EXPERT ,  { .func_arg = opt_thumbnail_format },
+        "set thumbnail format", "thumbnail" },
+
     { NULL, },
 };
-- 
2.17.1