lavc/options: extend/fix text for threads and slices options

libavcodec/options_table.h

@@ -342,7 +342,7 @@ static const AVOption avcodec_options[] = {
 #if FF_API_ERROR_RATE
 {"error", NULL, OFFSET(error_rate), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, V|E},
 #endif
-{"threads", NULL, OFFSET(thread_count), AV_OPT_TYPE_INT, {.i64 = 1 }, 0, INT_MAX, V|A|E|D, "threads"},
+{"threads", "set the number of threads", OFFSET(thread_count), AV_OPT_TYPE_INT, {.i64 = 1 }, 0, INT_MAX, V|A|E|D, "threads"},
 {"auto", "autodetect a suitable number of threads to use", 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, INT_MIN, INT_MAX, V|E|D, "threads"},
 #if FF_API_MPV_OPT
 {"me_threshold", "motion estimation threshold", OFFSET(me_threshold), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, V|E},
@@ -465,7 +465,7 @@ static const AVOption avcodec_options[] = {
 {"bottomleft",  "Bottom-left", 0, AV_OPT_TYPE_CONST, {.i64 = AVCHROMA_LOC_BOTTOMLEFT },  INT_MIN, INT_MAX, V|E|D, "chroma_sample_location_type"},
 {"bottom",      "Bottom",      0, AV_OPT_TYPE_CONST, {.i64 = AVCHROMA_LOC_BOTTOM },      INT_MIN, INT_MAX, V|E|D, "chroma_sample_location_type"},
 {"log_level_offset", "set the log level offset", OFFSET(log_level_offset), AV_OPT_TYPE_INT, {.i64 = 0 }, INT_MIN, INT_MAX },
-{"slices", "number of slices, used in parallelized encoding", OFFSET(slices), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, V|E},
+{"slices", "set the number of slices, used in parallelized encoding", OFFSET(slices), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, V|E},
 {"thread_type", "select multithreading type", OFFSET(thread_type), AV_OPT_TYPE_FLAGS, {.i64 = FF_THREAD_SLICE|FF_THREAD_FRAME }, 0, INT_MAX, V|A|E|D, "thread_type"},
 {"slice", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_THREAD_SLICE }, INT_MIN, INT_MAX, V|E|D, "thread_type"},
 {"frame", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = FF_THREAD_FRAME }, INT_MIN, INT_MAX, V|E|D, "thread_type"},